Overstocked and never ending diatom bloom, and observations.

[SparkyJones]

Ok so, my tank is overstocked, and I know that. But getting rid of fish isn't an option at this exact point. but here's the situation.
My tank has low KH, like 2dKH low. all my tanks run low KH as the source water is low KH and low GH, and the pH drops some if I don't do weekly water changes.
This tank is overstocked, and has had a diatom bloom going since november 2022.

If I water change the KH comes up and the pH also, to around 6.4 (my source water is 1dGH, 2dKH, pH 7.2) but this tank and the stocking WAS putting on like 15 ppm nitrates a day before the bloom started happening, and now it averages 10 nitrates from week to week never exceeding that and testing at 20ppm. I have to assume the nitrates are feeding the diatom bloom, there's no other explanation for what's happening. 1 week 10 nitrates, 2 weeks 10 nitrate, 3 weeks 10 nitrates, but by week 3 the water is just a hazy brown and you can't see the fish at the back of the tank, only if they come up front.
In those 3 weeks, the KH erodes and the pH drops again below pH6. I "think" the diatoms are consuming the nitrates and producing nitric acid and nitrogen gas. I think the nitrogen is released to the air, and I think the nitric acid is eroding the KH which then drops out the pH.

I don't think I can get rid of the diatom bloom without downsizing the stocking considerably, I know that, However I wanted opinions on what's happening, and wanted opinions on "what if I" scenarios.

: What if I add crushed coral to the substrate? A couple cups to buffer the KH and counter the acid? Obviously I will not lose the Diatom bloom,,,, or will I?

I kind of like that the diatoms are getting rid of the nitrates however it's a display tank and it looks terrible. 3 days after a water change and just gets progressively worse to day 7 and then week 2 its bad, and week 3 its REALLY bad, like a silty river after it rains and the sediment washes into it.
So I have an opportunity to experiment with this. the fish are fine, they tolerate the low pH without issue, My Ammonia and nitrite are non-existent, and the tank now shows a consistent 10 nitrates from week to week.

:What if I stop water changing and just test it for a few months, let the KH 0 and the pH drop again, and see if it exhausts itself at some point. I've gone as long as 6 weeks and it's just returned. basically clear for a day,

I mean clearly I'll need to downsize how many fish I have to a half or a 3rd or a quarter I think to break the bloom, which is unfortunate, I like the little fellahs and everyone is doing great. but I'm kind of curious if I stick some crushed coral in there to buffer the acids and maintain the pH and KH higher, if it might all stabilize and tone down.

Kind of wondering with this opportunity to try some things, what if I use a phosphate remover? it might also take out silica and cripple the diatoms.... What If I try something one of you mention and see if there's results? anyone have some ideas?
filtering hasn't worked, and While I'm sure I could likely polish the water temporarily, it's returning, already tried that they multiply too quickly.

for reference to the phenomena, this is a link to a science daily article about diatoms holding nitrates, apparently they store them and lay down a biofilm of their bodies on surfaces, and when oxygen is rough for them they convert the nitrates to O2 and ammonia again to keep living and then in an aquarium, I'd assume the nitrifiers turn the ammonia back into nitrates and then the diatoms store them and it basically just acts as a nitrate storage lock up and a cycle between microorganisms. I don't think it's quite totally understood how it all functions and the triggers. but interesting nonetheless.
https://www.sciencedaily.com/releases/2022/08/220831095024.htm

 

[TClare]

Could you try a UV sterilizer? That should get rid of any diatoms or algae in the water column I think?

Personally I would continue doing the water changes, although the angelfish won't mind the lower pH, other things can go wrong, TDS will increase etc.

Another thing you can do is add some water lettuce, that will suck up all the nitrates for you and outcompete the diatoms.

I don't quite understand how your general hardness is lower than the carbonate hardness?

 

[SparkyJones]

Could you try a UV sterilizer? That should get rid of any diatoms or algae in the water column I think?

Personally I would continue doing the water changes, although the angelfish won't mind the lower pH, other things can go wrong, TDS will increase etc.

Another thing you can do is add some water lettuce, that will suck up all the nitrates for you and outcompete the diatoms.

I don't quite understand how your general hardness is lower than the carbonate hardness?

I'd assume they both are around the 2 degrees. just GH is testing at 1 degree, and KH testing at 2 degree just happens to be the sensitivity of the test.

GH doesn't include KH and KH doesn't include GH, they are independent. You get the overlap with like a calcium carbonate buffer, where the calcium goes to GH and the Carbonate goes to KH and it parallels each other.

Appreciate the water lettuce suggestion, but there's a problem, the tank is on a big wet/dry filter and the HOB overflow prefilter is a surface skimmer type.
looks a lot like this:
PF-800 HOB Overflow - Eshopps
but I think it will suck up floating plants and I'll be digging them out of the overflow prefilter constantly.
I've never had any luck with plants.

I will look into a UV sterilizer, check on costs and function, I don't know much about it. But I feel like algae or diatoms, if it's not in the water column, the UV sterilizer won't get it. I need to check.
Thank you.

 

[TClare]

I think it will suck up floating plants and I'll be digging them out of the overflow prefilter constantly.

You normally just have to make a corral for the floating plants out of a piece of airline tube with suction cups at each end, this traps the plants where you want them and keeps the out of the filter outflow. Often as they grow they seem to hold themselves together and it is no longer necessary. But I will have to have a look at that type of filter as I am not familiar with it.

Its difficult to go wrong with water lettuce, just stick them in and clear some out every week once they get going!

Yes the UV sterilizer will only deal with what is in the water column, but I thought that was the main problem?

 

[cjcummings]

UV sterilizer won't do anything if the algae and diatoms are stuck on the surfaces. Anything that's in the water column that goes through the sterilizer unit would get nuked though.

I love crushed coral. It's not too pricey and easy to use. I'm just not sure how fast it will last / exhaust at the rate your tank is going through but once it stabilizes it should last a while before refilling/replacing. I vote to definitely give it a try. If anything just put it in a media bag and if you decide its not too your liking or you put too much, its very simple to just take out the entire media bag and adjust. Much better than plastering all over the substrate. I get it though. Touch choice between controlled nitrates or clear water lol.

 

[ruud]

I'd dim the lights massively and use pothos plants that receive light outside of your tank.

I think I understand your reasoning, but diatoms.... they are everywhere on this planet. What is a bit puzzling is why the diatoms are not replaced by other algae by now. If I find time to puzzle about it, I'll let you know.

 

[SparkyJones]

UV sterilizer won't do anything if the algae and diatoms are stuck on the surfaces. Anything that's in the water column that goes through the sterilizer unit would get nuked though.

I love crushed coral. It's not too pricey and easy to use. I'm just not sure how fast it will last / exhaust at the rate your tank is going through but once it stabilizes it should last a while before refilling/replacing. I vote to definitely give it a try. If anything just put it in a media bag and if you decide its not too your liking or you put too much, its very simple to just take out the entire media bag and adjust. Much better than plastering all over the substrate. I get it though. Touch choice between controlled nitrates or clear water lol.

I like this idea to try, I can probably pick up some media bags but I have a 5 gallon bucket of crushed coral sitting in the garage on standby from when I was keeping african cichlids. I could load a cup of it into a media bag and stick it into the wet dry in the flow and add a few cups that way and see what it does and remove it if it turns out to be not much or gets to be too much. I'm really curious if I can get the pH up closer to 7 and then let the diatoms just run their course without it dropping the pH and see if it dies off.
I feel like it's just spinning my wheels though to be honest but want to try some ideas. Pretty certain at this point I just need to reduce the stocking by half or a 3rd or 3/4ths to get nitrates under control which will then kill off the diatoms.... but I'd be kicking myself to no end IF I get rid of so many fish and it doesn't fix the problem....

Will bristlenose plecos eat diatom biofilm? maybe I can put a couple in there if they do?

What about lighting? I've heard that diatoms like low light conditions. I do have a fluorescent light on this aquarium, and yeah, the bulb is about a year old and probably not performing as it used to but it was a fish color light and not a plant light to begin with..... Anyone think maybe an upgrade finally to a 48" LED fixture might help with it?

and yeah, tank is great parameters, but kinda chocolate milk. looks good for a day or two after a 80% water change, and by the next weekend it's heading towards chocolate milk again. the diatoms don't hurt the fish at all but what's the point if you can't see the fish and everyone that comes over thinks I'm keeping a swamp..... hahahaha

 

[ruud]

Low light and diatoms is a myth. Hence a blackout kills diatoms fast. Unlike plants. The reason is storage of minerals. Plants store, algae don't.

Algae need more light and can do with less CO2 and minerals than higher plants, which are perfectly fine / better off with less light, but require more CO2 and minerals than algae.

 

[SparkyJones]

Low light and diatoms is a myth. Hence a blackout kills diatoms fast. Unlike plants. The reason is storage of minerals. Plants store, algae don't.

Algae need more light and can do with less CO2 and minerals than higher plants, which are perfectly fine / better off with less light, but require more CO2 and minerals than algae.

So, Getting a brighter full spectrum light won't help? or will help? I kind of feel like It would just trade diatoms for another algae, maybe populating slower than diatoms though, but then adding plants to use up nutrients and wind up with plants as a solution?

For sure the light needs to be changed if that heads to plants, I've never had anything grow in that tank besides diatoms.
CO2 may be necessary also, Not sure. It's a wet/dry, O2 I have in spades, not sure how much CO2 the tank retains.
I don't really want to have to change the light and the filtration, and they are angelfish, I can't go to a much faster flow it's not going to work for them long term. they need a slower flow.

I have come to the conclusion that most likely I have to reduce the stocking levels by at least half, maybe more in order to reduce the nitrate production. Although I realize this, I'm not happy about it and looking for "another way out" to end the bloom.

For all I know, if I water change the heck out of it now, hammer it even daily and wash surfaces and vacuum it, and keep those daily nitrates low and the stored nitrates in the diatoms that settle, and maybe it all dies off. on the other hand an average of a half a nitrate is produced per hour, I'm not sure that will end it though. Water changing and filtering hasn't ended it yet and been 5 months but I also haven't really hammered on the water changes in a while either going to weekly 50-80% or 2x a month or 1x a month to see if I could exhaust it and get a die off.

I haven't tried Seachem Phosbond, its a phosphate silicate remover. Worth a shot, or a sham?

 

[ruud]

I'm just gonna repeat Sparky, grab a few pothos plants from a garden center, remove all the sand, stick the roots in the tank, and keep the lights in the tank off for a few days, or at least much dimmer than the current lamp I always witness on your tank, but make sure the pothos get plenty of light, and watch miracles happen.

Changing water parameters might also work as I believe diatoms are restricted to certain salinity and ph conditions, meaning, different diatom species (how many are there? 10.000s? 100.000?) inhabit different salinity and ph conditions. So no idea, what it will cause.

But as I am so convinced about the importance of light intensity (and not the quality or duration of the light), I'd stick to this solution, along with adding the roots of emersed plants.

 

[TClare]

I am quite sure this approach will work. But if you have a lid on the tank and can't use Pothos, water lettuce will do the same thing, I promise!

 

[Flyfisha]

I only read some of the posts. Did anyone question the substrate choice?

The only time I had on going diatoms that only got worse with time was when I was trying a different sand. Although sold as aquarium sand this particular black sand likely had the building blocks of diatoms in it. Once I removed that brand of sand the diatoms stopped almost overnight.

Pothos needs a minimum of a 1/8 inch /4 mm slot in the lid to access the water.

Edit ,
No BN don’t really eat much in the way of diatoms . I am sure they would eat it before they starved to death when no other food is available? However casually adding “ a couple “ to an already overstocked tank would be a mistake in my opinion. They breed when wet and are known poop machines.

 

[SparkyJones]

I only read some of the posts. Did anyone question the substrate choice?

The only time I had on going diatoms that only got worse with time was when I was trying a different sand. Although sold as aquarium sand this particular black sand likely had the building blocks of diatoms in it. Once I removed that brand of sand the diatoms stopped almost overnight.

Pothos needs a minimum of a 1/8 inch /4 mm slot in the lid to access the water.
View attachment 875613

The substrate is sedimentary river rocks and slate, also there's some petrified wood. No sand.

 

[SparkyJones]

I went window shopping and saw this thing, it's an I tank filter with a UV by aquatop.

Anyone know this product or had experience with it?

 

[ruud]

Perhaps I have another suggestion.
I recall you had/have a GH? Or is this no longer the case?

 

[SparkyJones]

Perhaps I have another suggestion.
I recall you had/have a GH? Or is this no longer the case

Appreciate it! but thats no longer an issue, GH is 1dGH and parameters all all now in line with my other tank. pH is 6.8, 4dKH, 1dGH. 0 ammonia, 0 nitrites, 10 nitrates consistently and doesn't exceed it even if I don't water change for a month now I don't think it can get past the 10 nitrates, the diatoms just keep getting thicker.

Diatoms are still out of hand though, they have to be consuming the nitrates. 24 angels should be putting on like 15 nitrates a day maybe even more, they used to before the diatoms appeared.
The fish look fine and are healthy, the water parameters are good also. no funky smells, the water is bad looking though.

This weekend I will try an 80%+ water change, and put in the 50 micron filter pad in the wet/dry, and also on the in tank filter (the regular filter floss doesn't catch much of this at all so it's been useless so far) See if this works,,, but I'm sort of at the point where if I want it to actually end I'm going to have to give up some fish and reduce the nitrate production... that or maybe change lighting and add a ton of plant which I don't really want to do because plants are just another headache for me.

So yeah, gonna try this and see if I can water change it down (I know this works temporarily) then capture the last of it in the filters and remove it. if that doesn't work, Looks like I'll be trying to rehome a dozen angels for a start, and see where that gets me. It's still basically this in a couple days after a water change. And been doing it for a good 6 months now.


I think I'm just going to have to rehome 1/2 to 3/4th of the fish to get clear water and break the diatom bloom. Just too much nitrates and right pH for the diatoms to thrive I guess.

Honestly I don't mind the cloudy water, but it looks bad to other people and tired of explaining whats happening and that it's not "dirty", and I would like to see the fish once in a while without needing them to swim up to the front of the glass.

 

[cdr63corv]

Found this thread very interesting. I to have a kh of 2 in one of my tanks, and noticed algea seems to grow pretty fast in there. Read limestone will raise kh and have put in quite a few limestone rocks. I have been on the road working for a couple months and haven't checked it since getting home. Please post what you find out and good luck

 

[kallililly1973]

You might be able to add a few otto cats or nerite snails to help with the diatoms

 

[SparkyJones]

You might be able to add a few otto cats or nerite snails to help with the diatoms

I wish it was something they could handle but its so out of hand normal filtering can't control it. Gonna try the 50 micron pad and see if it will capture enough to cause a collapse of the mature larger diatoms and hopefully pick off the smaller ones before they multiply again.
It gets like the picture in about 5 days from near clear. The only things I haven't tried is
-Reducing the stocking.
-Plants and additional lighting to establish a higher order nitrate consumer.
-100% water change hoping to just wipe them out completely.
-the 50 micron filter pad.
- establishing a bed of freshwater bivalves in the substrate to eat the diatoms.
- plecos and ottos, just be more nitrates and more suspended diatoms. I just don't see how they could keep up with their multiplying.

I'm about to get a silicate test to confirm or rule that out but at the rate they populated won't crash, maybe soluable silicates are that far out of order somehow.. seems odd though, drives me crazy it won't end like any other time it's happened over the years.

 

[Perfect]

It is possible that you can create competition for nutrients via a more efficient nutrient exporter. If you had a sump you could probably use plants that grow fast (invasive even) which could cause the amount of diatoms to thin out.
That's what I would do however (currently doing this in my SW setup).

 

[TClare]

Floating plants like water lettuce could help a lot, and have you tried a UV sterilizer? Having said that I do think it would be best to reduce the numbers of fish, they are really too crowded to exhibit normal behavior long term.

 

[Cherryshrimp420]

This seem perfect for a deep sand substrate. The sand will allow growth of a variety of microorganisms including nitrifiers and denitrifiers that will help with your fish waste in the absence of plants. It's essentially doing the same function of plants with nutrient uptake.

Check out Father Fish youtube channel for some examples. Especially in some of his older videos when his shop was open. He had heavily stocked monster fish tanks with 10"+ of sand in some.

(11min+ mark you can see some angels and monster fish after that including bass, clown knifefish and more)

 

[SparkyJones]

Floating plants like water lettuce could help a lot, and have you tried a UV sterilizer? Having said that I do think it would be best to reduce the numbers of fish, they are really too crowded to exhibit normal behavior long term.

Floating plants will just all wind up in my wet/dry filter.
I haven't tried a UV sterilizer, not wanting to pull the trigger on that just yet for the cost of them.
I dunno,. everyone is doing well past year one, eating well, nice color, no severe fighting or nipping damage at all, schooling/shoaling behaviors within the group. there's no stress and no stress behaviors going on.

I agree that I will have to reduce the numbers as a solution most likely and coming to terms with that, but it wouldn't be from crowding or behavior as a reason, it's solely based on not being able to break the diatom bloom with it the way that it is and it just not looking good. I will however really kick myself if I give up half or more of the fish and the diatoms persist still and it wasn't the solution. I'm likely going to try everything that I can and see if something works first. Thank you. The UV sterilizer isn't off the table just on my delayed due to cost list.

I think the LED lighting upgrade will need to happen first, just for generally really needing it.
I'm still on 4 ft fluorescent and that might have SOMETHING to do with it, or at least the inability to grow green algae or plants. I'd think if I could grow algae it would rob the diatoms, a different problem, but a better problem unless its the green water type algae that puts me in the same boat of a different color.

It is possible that you can create competition for nutrients via a more efficient nutrient exporter. If you had a sump you could probably use plants that grow fast (invasive even) which could cause the amount of diatoms to thin out.
That's what I would do however (currently doing this in my SW setup).

I've given this some thought, I do have a wet dry and I don't think it would be all that difficult to install a light underneath int he cabinet and stick some pothos or something down there. after the bio section but before the return pump section. Not sure how effective something like that could be. I've tried like Pond matrix, and while there was some benefit, it wasn't like "amazing" results so I abandoned using it as very little benefit for the cost. it was before this bloom though.

I've looked at the mainepure blocks also. was thinking to bury under my river rock, or chuck one into the wet.dry or a combination of both and see but kind of feels like it will have the same result as the Matrix.

I don't have a sump, though, theres minimal space I could do something with int he wet/dry before roots or something get into the return pump I'd think, which is why I haven't tried to put something down there. thanks for the suggestion.

 

[TClare]

Floating plants will just all wind up in my wet/dry filter.

Oh yes I remember you said that, I am not familiar with that filter but would it not be possible to make a corral for the plants with airline tubing, this should stop them escaping and getting into the filter?

 

[SparkyJones]

So I bought the in tank water polisher and changed pads to 50 micron about 2 months ago. It didn't seem to do much difference.
I stop water changing for the last 6 weeks what has happened over that time was the KH dropped out again and the pH dropped.

In the last two days it's been clearing up again, but I feel like it's because the tank is getting too acidic for the diatoms. Definitely it's related to the pH KH and nitrates. First month before the KH depleted the diatoms were doing their thing and nitrates at 10ppm consistently. Last week or so when the KH depleted and pH dropped again to pH6, it started to clear and the nitrates are back, between 50ppm and 100ppm and rising.

Overall the answer is to reduce the stocking, to reduce the nitrates.
I've tried everything I can think of except plants or dumping in a ton of crushed coral.




I'm going to try to water change which will give me KH and pH rise again, if the diatoms come back it pretty much confirms it that the answer is to reduce the stocking. I'm doubting this Clear up was just the natural end of the bloom, I think it just got too inhospitable for the diatoms with the acidity...

 

[TClare]

Floating plants (with corral to prevent them getting in the filter) and UV sterilizer?

 

[SparkyJones]

I'm iffy on the expense of a UV sterilizer when other methods didnt' seem to work all that well.

With the diatoms it stays at about 10ppm nitrates. without the diatoms like now, it's putting on something like 100 ppm nitrates a week, maybe even more (I only have the data from before the diatoms appeared and the fish were smaller then). It took like 5 weeks without water changing hoping to starve the bloom, for the nitrates to burn off 4 dKH and drop out the pH.

I'm kind of doubtful I can cram in enough plants to remove that level of nitrate production, and then theres the cost of them.

info I found was
"Plants placed in nutrient solution containing 0.025 mg/l of nitrate-N required 18 hours to take up the nitrates. However, similar plants placed in nutrient solution containing 0.025 mg/l of ammonium-N required only 3.9 hours to take up the ammonium"

If, and I'm ball parking as my best estimate, something like 15ppm a day, or 0.63 ppm nitrate an hour.
I just don't see plants being able to dig out that kind of hole, I mean it looks like 125 plants, and that's just to 1 hours production while it takes 18 hours to clear the one hour...

I'm not good at math, just seems like I'd need 2000 plants or more to zero the nitrates, now it might go faster if it takes from the ammonia before it's converted. but still I'm thinking somewhere near 400 plants.

I've contemplated piping from the wetdry and using my back room as an aquaponics grow room, it's like 80ftx20ft. but thats not cost effective at all.

I've just come to the conclusion that I can either wrestle with it, and water change 2x a week,
or I need to get rid of 75% of the fish,,,, or spend varying levels of a larger fortune to work something else out that can use up the nitrate production around the clock.

I'll know that for sure that the fish have to be reduced when I water change this weekend and bring up the KH and pH, if the diatoms return it's basically just telling me it's unsustainable.
I'm contemplating riding it out 1 more week of nitrate rise, to maybe be a little more certain the blooms been killed off.

it's a 4ftx2ft deep tank, I really like it this active, and as far as the fish they are healthy and calm and all that and in great condition currently, but the level of work to keep it up is out of hand without the diatoms helping,
And if I don't do the work and let the diatoms do it instead, then it's perpetually cloudy from the abundance of diatoms thriving on the nitrates and I can't really see the fish....
... and if I don't do the water changes to keep the nitrates down when it's clear, the fish will suffer.

I don't think a plant or two, or a dozen will dig out the pile, maybe a small farm of plants. I've got what amounts to "aquaponics" stocking levels currently. which is great if I had a large enough nitrate sink to take up all the nitrates, in aquaponics, the nitrate production burns off the KH, and the pH drops making the ammonia ammonium and a low pH system safe for the fish like tilapia, and then maintaining the nitrates with plants between 40 and 80ppm ensures good growth of the plants, and without detrimental effects on the fish. at least that what the aquaponics research scientists say. the 20ppm nitrate or less of the hobby is "optimum health and conditions" for the fish, however, as far as aquaponics goes, the plants would starve so they run much higher.

Jeesh, I've even looked in places where theres more research being done than in the hobby.

from another article I found:
"When nitrate is produced from ammonia, alkalinity is depleted at a rate of 2.3 dKH for each 50 ppm of nitrate produced."

Just kind of all boils down to having unsustainable stocking for the volume of water, (not with out a ton of work at least to keep it viable) and needing to reduce it. even f I got clear water, and plants, the nitrate production would still kill the KH and drop out the pH unless I'm water changing 2x a week at 90-100%. even then the nitrate flow is constant, I'd be doing the change to lower the nitrates, but it would actually be to replenish the KH.

Maybe a buffer, like crushed coral substrate, but then I think I'd be dealing with the diatoms again.

Yeah,.... it's overstocked, and the signs all say "unsustainable". I flew to close to the sun....

 

[drat]

I did not read all the posts, so I may have missed it, but did you ever try the crushed coral to raise KH? If you want to try it without messing up your substrate put it inside a mesh bag in the filter. That way you can remove it if it is not producing the desired results. I don't know that it will help with diatoms, but it should help get kh, and ph up and stable.

 

[Flyfisha]

Hey SparkyJones ,
Our commonly held belief that a water change routine should be based around a 7 day week is misguided. It’s of help to people who have a weekend break from work or school. All I am saying is a 7 day routine has nothing to do with fish keeping and everything to do with a working week.

I have no angels in my life but have on many occasions when growing out batches of juvenile fish had to do water changes multiple times per week.
I currently have approximately 50 Bolivian rams that up until recently were all in a 55 gallon. To my way of thinking the water needed changing often as I was feeding multiple times a day. Even now i have some in a 40 gallon to spread the poop load from multiple feeding I still change water at random times as well as each “ water change day .

The point of my rambling.
Just change the same amount of water you change now but do it more often . You know the tank is heavily stocked.

Thoughts on the use of coral.
My water does not require it but many people do use it to increase KH I believe?

The cost of pothos.
You need only one plant to propagate dozens in just a few weeks.
Yes just breaking of a long stem will give you another plant but if you want faster individual growth this is how you propagate it.

The cuttings can go straight into water.

 

[SparkyJones]

I did not read all the posts, so I may have missed it, but did you ever try the crushed coral to raise KH? If you want to try it without messing up your substrate put it inside a mesh bag in the filter. That way you can remove it if it is not producing the desired results. I don't know that it will help with diatoms, but it should help get kh, and ph up and stable.

I havent' tried it on this. I used to keep african cichlids like that decades ago, it will counter the nitrates and acids from the conversion, so the KH can stay up with the pH, but this doesn't address all the nitrates, which is the real problem overall. I don't care if the KH is gone and the pH is 6, the fish dont' care either.
it's just that I can either have a bloom of diatoms and like 10 nitrates, and chocolate milk water and do water changes frequently to be able to see the fish,

Or I can have it clear and pH6 and 0 KH, and 100+ nitrates a week and have to do frequent water changes to keep nitrates down which will likely get me varying levels of diatom blooms when the pH comes up.

Or I can reduce the stocking to much saner levels, reducing the nitrate production, and making everything healthier, better looking, and easier on water changes for me.

AQ Advisor warned me.... I didn't listen... Hahahaha

Hey SparkyJones ,
Our commonly held belief that a water change routine should be based around a 7 day week is misguided. It’s of help to people who have a weekend break from work or school. All I am saying is a 7 day routine has nothing to do with fish keeping and everything to do with a working week.

I have no angels in my life but have on many occasions when growing out batches of juvenile fish had to do water changes multiple times per week.
I currently have approximately 50 Bolivian rams that up until recently were all in a 55 gallon. To my way of thinking the water needed changing often as I was feeding multiple times a day. Even now i have some in a 40 gallon to spread the poop load from multiple feeding I still change water at random times as well as each “ water change day .

The point of my rambling.
Just change the same amount of water you change now but do it more often . You know the tank is heavily stocked.

Thoughts on the use of coral.
My water does not require it but many people do use it to increase KH I believe?

The cost of pothos.
You need only one plant to propagate dozens in just a few weeks.
Yes just breaking of a long stem will give you another plant but if you want faster individual growth this is how you propagate it.

The cuttings can go straight into water.

Appreciate it. just saying it's not my first trip to the rodeo and have raised fish from eggs also and do the water changes daily even.
however, the level of water changes this requires even with a water changer is out of hand. I'm just not going to water change 1000 gallons a month and more just to keep cloudy water a bit less cloudy I've had enough of it honestly.
I was doing this tank 90% 2x a week which keep the diatoms lower and the water hazy, I went to 90% 1x a week which by day 7 had the water looking like the earlier picture by day 7.

I tried just to let it go to see if it would starve off the diatoms. Well the diatoms died off just recently after 6 weeks, first 4 weeks it was chocolate milk and 10ppm nitrates consistent but around week 5 the KH depleted and the pH dropped out and it's just clearing right up. but nitrates are shooting way up again.
I feel it's due to the pH dropout more than anything for the reason behind the crash of the diatoms.

I'm just reaching the point where It's not something I want to do anymore. I like the activity of the fish and dont' want to give them up, and would like to keep it this busy,
however I'm just tired after all of this and want things easier, a simpler time, less water changes, less murky water, less headache. and more enjoyment.

I don't really want to add plant keeping into the equation also maybe its' easy, but to me it's just another thing to do and I'm at the point where i want to simplify things.

 

[TClare]

Yes, the best answer is to reduce the number of fish. I am sure a UV sterilizer would get rid of the diatoms in the water column, but you would still be left with the issue of very high nitrates. I strongly believe that floating plants or Pothos would help considerably. Several years ago I bought a tiny piece of water lettuce for a dollar, now I have it in all my tanks and throw away large amounts each week. My nitrates are always very low, even zero in one tank if I don't add fertilizer, however none of my tanks is very heavily stocked.

 

[Perfect]

Are you doing water changes?
I suppose you have to since you are so stocked but I actually had problems with Cyanobacteria in my saltwater tank and for the most part I have beaten it by NOT doing water changes. The problem is that whenever I would change a significant amount of water, the sudden replenishing of trace elements would fuel growth and would overrun everything.

I guess lightening your bioload and MAYBE trying something like that could work. I dunno. Can't think of much.

 

[drat]

Or I can reduce the stocking to much saner levels, reducing the nitrate production, and making everything healthier, better looking, and easier on water changes for me.

Or you can buy a giant pleco that will eventually worsen your overstocking problems, but eat the diatoms! LOL, we all know that is what we would probably do! LOL!

 

[TClare]

I actually had problems with Cyanobacteria in my saltwater tank and for the most part I have beaten it by NOT doing water changes. The problem is that whenever I would change a significant amount of water, the sudden replenishing of trace elements would fuel growth and would overrun everything.

I am not sure about saltwater, but in freshwater cyanobacteria tends to appear when nitrates are very low (or low compared to phosphates). So not doing water changes would increase the nitrates making the tank less suitable for cyanobacteria I suppose.

 

[SparkyJones]

I am not sure about saltwater, but in freshwater cyanobacteria tends to appear when nitrates are very low (or low compared to phosphates). So not doing water changes would increase the nitrates making the tank less suitable for cyanobacteria I suppose.

yes, the theory is if nitrates are too low, the cyanobacteria will capitalize on the phosphates and take over
and by bringing the two into balance will "square" the imbalance and cause a situation where the cyanobacteria can't thrive anymore because the ideal situation doesn't exist to thrive.I'd think by not doing water changes, it would have to make the nitrate and phosphate meet at some point, reach an equilibrium and die off. this applies to salt and fresh basically equally.

Nitrates and phosphates are consumed by bacteria in a 16:1 ratio, known as the Redfield Ratio. (it's actually 106 Carbon: 16 nitrogen : 1 phosphorus.)
If you don't have the nitrates/nitrogen, bacteria/phytoplankton can't consume the phosphates and you wind up with low to no nitrates once they are exhausted, while getting a run up on phosphates which cyanobacteria can use basically only. Nobody is going to run out of carbon.
Some Cyanobacteria like Diazotrophic Cyanobacteria will capitalize on the phosphates and convert them into Ammonia which can then become nitrates to create a balance when nitrates are in short supply in the natural environment like aftican rift lake for instance with the seasonal stratification. it can't be replicated in an aquarium though, but that would be the natural process for a rift lake, or an ocean to take phosphates and convert them into nitrogen so the system can re-balance to the ideal, which is that redfield ratio needs being met. the algae, cyanobacteria, it's all doing it's things based on this ration, and abundances cause blooms.

Like me,. My tank isn't conducive to algae above diatoms. I have a huge abundance of nitrates, and likely not much phosphate would be my guess, maybe none at all actually, it's the one thing I didn't check.... and well there's probably plenty of carbon, but at 16:1 I just have more nitrates than can be used up and the diatoms stepped in to capitalize on the abundance. I'm sure if I got full spectrum light I could then turn those diatoms into some other higher form of algae.

Maybe I should test my phosphates, see if they are nil, and if so, try adding some, it might promote bacteria activity and get more nitrate consumption going by the bacteria...... Hmmmmm....
Honestly wouldn't have thought of this unless this little conversation popped up. Thanks, I now have a tangent to follow, but perhaps If I can increase the phosphates, I can get a larger bacteria colony and they can use more nitrate and come to balance, kind of opposite of the Cyanobacteria strategy... but I feel like this leads to the denitrification rabbithole and probably requires hypoxic conditions as they all do to denitrify. .....

not doing water changes has worked in a way, it's eaten up all my KH and dropped my pH, and I think that acidity has ended the diatom bloom. I don't think diatoms in general have a problem at any pH, but I think the specific species I have has a problem below pH 6.4 and it dies off, and reappears as the pH comes up, maybe just what there is in south florida since diatoms are everywhere, I've always had diatoms unless the pH was shot out, but to a far lesser extent when it was 4-8 fish just a minor annoyance of dusting on surfaces.. When I overstocked african cichlids I had to turn over the crushed coral pretty regularly and flip the stones over or it would all be coated in brown. same issue though, nitrate production issues.

 

[Perfect]

If upgrading the tank is not an option, perhaps increasing the amount of rock in the tank could increase bacterial growth and be able to suck up the bioload but then again there isn't much space. This is a tricky one without reducing the amount of fish in the tank.
You might not be able to eliminate the problem without introducing another organism that can absorb the nutrients more efficiently.

 

[SparkyJones]

If upgrading the tank is not an option, perhaps increasing the amount of rock in the tank could increase bacterial growth and be able to suck up the bioload but then again there isn't much space. This is a tricky one without reducing the amount of fish in the tank.
You might not be able to eliminate the problem without introducing another organism that can absorb the nutrients more efficiently.

It's on a wet/dry trickle filter with about 5 gallon bucket of bioballs of surface area for bacteria. Nitrates are over 100ppm today pH at 6 KH at zero again. Fish are all fine and everything looks great.... I'd agree. I think if I did change the lighting to full spectrum the diatoms would get outcompeted by algae, but I think I just change brown water for green water and brown stain patches for green stain patches.

This morning:

Because of the nitrates building up now this doesn't work either but the diatom bloom did end, now I'd just need a method to use about .50-.75 ppm of nitrate and hour, every hour around the clock. Short of that stocking must be reduced to actually get a balance long term.

 

[Decoy]

Hi Sparky,

This product comes to mind when I read your thread... Please have a read, I use to use it in my tanks, just pop a small bag full of it in your filter... And it is reusable too....

Seachem - Purigen

 

[SparkyJones]

Just read it and want to look into it further. I've tried pond matrix last year for a few months but it couldn't keep up and was still stacking nitrates, more slowly, but was still doing it.
Maybe a combination of purigen and matrix or marine pure block..... combined maybe it will give some breathing room. Filter space I have.

I think I'm gonna ask some questions about marinepure in the saltwater section, looking at other forums it seems to be the superior product for denitrification over matrix but not sure if it's actually more effective $50 per block is kinda steep also if it ends up doing nothing.

 

[Decoy]

I would personally just try 1 product at a time, that might be the problem...
You can buy a bag of purigen for $20, just check its size verse your tank size..

 

[SparkyJones]

I would personally just try 1 product at a time, that might be the problem...
You can buy a bag of purigen for $20, just check its size verse your tank size..

I normally just use the filter floss and fine micronpad and prime only ever. I tried matrix but the nitrate reduction took a long time to start, and then wasn't a whole lot to make it worth the cost so I abandoned the idea after 4 months and results plateaued. I'm not an "additives" person and don't even use medications unless absolutely necessary.

The marinepure is just like a manufactured pumice rock like a brick or paver that can harbor denitrifiers in its interior and nitrifiers on the exterior. I wasn't thinking it would be a problem and just additional biofiltration.

 

[cdr63corv]

My wife had some spider plant babies, read online how you could put them in your tank. Just hung them down so the roots were in the tank and was amazed with my water test readings. Haven't seen over a 10 reading on nitrates, usually a 5 or less. Granted not nearly as stocked as your tank but definitely think it would be worth a try and they're cheap. Honestly wish you the best of luck.

 

[Decoy]

SparkyJones Hey, I am interested to know, did you try the purigen at all? Or has anything else worked since the last post here?

 

[86 ssinit]

Hey sparky! Just reading this. I’m with the more water change crowd. Or a bigger tank. Or more filtration.
Ok next when you used the water polisher was it a polishing filter or polishing pads added to the wet dry? Im guessing the tank is a 150g. How much water are you moving in your wet/dry? Is the wet/dry the only filter.
I have magnum polishing filters. These filters will clear your tank in an hour. Then when clear I’d stir up the substrate till the water was brown again. When clear I’d stir again. I’d let that thing run till the flow was half. Add another filter pad and stir it up again. Let it run for a few days till the water was crystal. Then just changed water once a week.

 

[SparkyJones]

SparkyJones Hey, I am interested to know, did you try the purigen at all? Or has anything else worked since the last post here?

Not yet on the purigen. I've done nothing at all so far except enjoy the clear water and watch the fish for signs of a weakened immune system/degradation of appearance or sign of stress from the nitrates. my pH is for sure now down below 6.4 even. it's probably below 6.

Sorry, it's been since September 2022 since the tank has been crystal clear (when it was a disaster on nitrates and GH was through the roof)
I need a couple weeks being able to see the fish clearly before I go water changing or messing with it in case the bloom appears again when I water change the KH and pH back up..... but I'm keeping a close eye on the fish.

Nitrates are around 100ppm currently (likely on the high side of 100ppm) . GH is still like 0-25ppm. and KH is zeroed. There's just so much acid that gets created from nitrification. Not sure what really could deal with that. When it comes to this, most of the products are for a "small" problem, not a "big" problem. sort of a bandaid so people can stretch out water changes further. I kind of have faith in the purigen, the more I read about the marinepure blocks the more I think that might be the way to go and hope for some decent denitrification out of it.

Hey sparky! Just reading this. I’m with the more water change crowd. Or a bigger tank. Or more filtration.
Ok next when you used the water polisher was it a polishing filter or polishing pads added to the wet dry? Im guessing the tank is a 150g. How much water are you moving in your wet/dry? Is the wet/dry the only filter.
I have magnum polishing filters. These filters will clear your tank in an hour. Then when clear I’d stir up the substrate till the water was brown again. When clear I’d stir again. I’d let that thing run till the flow was half. Add another filter pad and stir it up again. Let it run for a few days till the water was crystal. Then just changed water once a week.

The Wet/Dry. it's a 150 size something around 24"L x 15"W x 18"D, the tank is a 72g. the wet/dry has a return pump that's 800 GPH. I used to run it at 1500 GPH for african cichlids back in the day but that would just blow angels around so I bought a smaller one that would do right around the 10x an hour.

I bought an Odyssea EX350 Internal power head type filter and put a layer of 50 micron filter pad on it with an outer layer of the filter floss. The wet/dry has a 15"x15" sheet of 50 micron filter pad and a layer of the filter floss on top of it to keep the bigger stuff out of the fine pad. Plus I use a coarse prefilter sponge in the overflow box.for the largest stuff to keep it out of the wet/dry.

Doing the 50 micron pads and additional filter prolonged it but it never got clear, it just took longer to get murky and look like river flood water. Clearest day was water change day and it was hazy still even with a 90% water change. The diatom bloom was intense to say the least about it.
As long as the pH was above 6.4 the bloom was rocking hardcore. Once it dropped below pH 6.4 it cleared in a day. the 50 micron polishing pad helped, but it didn't catch the smallest diatoms that were under 50 microns in size.

I mean, this was it about 7days after a water change of 90%.

this was it with the polishing pads and internal filter after a 90% water change

And it came back, just slower.

Once the pH dropped below 6.4

\
It's even clearer now.

it's just not sustainable without massive water changes, and not sure if I could break the diatoms doing that either if I did. I'm just crossing my fingers I can water change, and bring up the KH and pH and not get a diatom bloom this time, stalling for the "have to" moment while it's clear. and hoping they all die off and don't return.
The water bill is high enough. going bigger isn't an option and daily 50 gallon water changes for a murky tank isn't an option either, it defeats the purpose of having an aquarium if you can't see the fish. '
Will see how it goes. if the diatoms return I will most likely downsize the fish to 6 and do some other smaller fish with them to fill it out, maybe bristlenose or something along that line but small, and some corydoras. maybe some rams or apistos or a handful of hatchetfish.
We will see when I do the water changes to bring it back up how it goes. I feel like re-homing the majority of them is the option though.

the light is fluorescent, I was looking at the bulb and it's getting the dark spots, so it's probably worn out. I may try a more full range bulb (this one was for color rendering) But maybe its time to just go LED, but I don't think I can take exchanging run amok diatoms for run amok algae. I'll lose my mind.

 

[86 ssinit]

Ok I see people keeping this many discus in 75g. Thing is they never really grow to the right size. Many end up stunted. Wet/dry moving 750gph and the 350 bringing it up to 1100gph I’d think would keep it clean. How often are you cleaning the filters? Also move the odyssea to the right or left. Not in the center. I change water twice a week and the sponges in the odyssea are filthy.
Time to move to led lights. Look into the hygger 975. This light has an 8 time cycle timer that you can adjust the intensity. As in you could leave it at 30% for the day. Still have light but not giving the diatoms the light they need.
Next a 150 is 48x24x24. Almost the same footprint .
How many angels in the tank?

 

[SparkyJones]

Ok I see people keeping this many discus in 75g. Thing is they never really grow to the right size. Many end up stunted. Wet/dry moving 750gph and the 350 bringing it up to 1100gph I’d think would keep it clean. How often are you cleaning the filters? Also move the odyssea to the right or left. Not in the center. I change water twice a week and the sponges in the odyssea are filthy.
Time to move to led lights. Look into the hygger 975. This light has an 8 time cycle timer that you can adjust the intensity. As in you could leave it at 30% for the day. Still have light but not giving the diatoms the light they need.
Next a 150 is 48x24x24. Almost the same footprint .
How many angels in the tank?

23 adult angels and 1 adult blue gourami that just keeps on kicking. Been changing filter pads once a week, prefilter sponge gets rinsed daily. .
Center and mixed with the return nozzle for the wet/dry is the only place the angels will tolerate it and use the whole tank, on the left or right, they all want to be on the opposite side of it away from the flow. between the wet/dry return nozzle and the odyssea, in separate places they avoid half the tank. where the flows are.

Not sure what you are talking about exactly on " Next a 150 is 48x24x24. Almost the same footprint "
a 150g tank is 72″ x 18″ x 28″, my tank is 48″L x 18″W x 24″H 6 ft vs. 4ft. and double the water volume.
a 150 wet/dry is generally 24"x12"x16" or some variation of that depending on the manufacturer. it's roughly a 20g aquarium.

I was looking but can only find the Hygger 978 now, not sure if the 975 is obsolete or what happened though.

 

[Blacksheep1]

I’d be tempted to say purposely crash it and stick a TONNE of botanicals in it to take over the cycle ( only because I know you are experienced enough to handle it ) but it’s way too over stocked to take that. Also the bacteria at that ph is much slower growing and would take time , that’s why with your stocking it isn’t really an option. The angels could take it though, if less of them.

What’s the long term plan for this tank? Just keep it as is for the life span of the angels ?

just to be super clear for anyone else reading , don’t crash a tank on purpose if you don’t fully understand it !!!! Just a disclaimer before anyone comes for me

I do find the correlation between low pH and kh and clearer water an interesting one though. Have you tried any botanicals at all ?

 

[SparkyJones]

I’d be tempted to say purposely crash it and stick a TONNE of botanicals in it to take over the cycle ( only because I know you are experienced enough to handle it ) but it’s way too over stocked to take that. Also the bacteria at that ph is much slower growing and would take time , that’s why with your stocking it isn’t really an option. The angels could take it though, if less of them.

What’s the long term plan for this tank? Just keep it as is for the life span of the angels ?

just to be super clear for anyone else reading , don’t crash a tank on purpose if you don’t fully understand it !!!! Just a disclaimer before anyone comes for me

I do find the correlation between low pH and kh and clearer water an interesting one though. Have you tried any botanicals at all ?

yeah, It's already crashed. nice and stable and registering the pH at a color thats a yellow that doesn't head green at all compared to the API chart. I need a pH kit that can go lower to know for sure. KH same thing 1 drop turns it blue immediately. Probably it would do it with even less than 1 drop if I could. Strip test says its below 6.4 which is as low as that test goes and the KH is yellow and the chart says zero, Both the KH and pH are the same shade of yellow on the test strips.
No plants and high Oxygenation so theres no fluctuations others might see. it just sinks over time downward as the KH gets depleted, and doesn't bounce around, if I restore the KH through water change, The pH will come back up, but I'm in that position now where I'll need to do 20% changes over time to bring it up.

I seriously thought of this "low pH tank" , but yeah the problem is the nitrates from the overstocking.
I think the acidity killed off the strain of diatoms that is prevalent where I am.
No botanicals have been tried. Unless they can remove nitrates, It's a wasted effort.

I'm not so worried about the cycle, I've transitioned the tank from this situation before back up and it was a much much deeper hole. there's a very brief period of concerningly elevated nitrites in the 5-6 ppm range for a couple days, but it clears out quickly and from the tap I've only got like 3dkH and a pH of like 6.8 so I don't think when I get to pH6.4, I get ammonia and get ammonium instead, and the nitrites don't seem to cause a problem either. There's ZERO risk of me getting to pH 7.0 or higher also without a pH up buffer being used.

The issue is once I get to pH 6.4 and higher the diatoms go crazy on the nitrates, and not the just the buildup, the daily production, as it's happening. I'm hoping this time I've killed off the diatoms and they don't return when I do the water changes to bring it up, but that IS the most likely outcome, that the diatoms return with the pH increase.

Long term plan for this tank was 12 maximum angels in a shoal, thinking like 9 tops now because of the "little issue".
I kind of overdid it trying to play it safe and kept 24 to adults to cover the rehoming of females and account for possible dieoffs before maturity. Well, in 16 months only one female appeared of the group and nobody died off. I have hope there might be one or two late bloomer females left. hahaha,Yeah right.
Anyways, a small shoal of males 6 maybe 8 or 9. then add some other smaller but not too small amazon type fish to fill it out. Maybe a pair of L180 plecos if I can find them, maybe a couple german blue rams and a few hatchet fish.

it was the idea..... kind of stuck at the moment enjoying fish I haven't seen well in the past 9 months of diatom bloom. If it returns I'm going to try to take 12 to the LFS to be rehomed and cut it in half, hopefully that works or at least buys time and makes it easier so the LFS can get rid of them before taking some more to them.

Not even sure they will take 12 at once, I've only ever seen them with a pair to 4 adults at one time. even the juveniles they only want 20 or so at a time.

 

[86 ssinit]

Sorry hygger957 and a 120g tank. It’s 48x24x24. Just 6” wider.
You’re replacing the filter pads weekly. Is this from the odyssea? If so just run 1 pad and 1 sponge and rinse both don’t replace. What’s in the wet/dry. Can you put up a picture?