180 Gallon Tank 0 Nitrates Is So Easy, Why Does No One Do It?

Or think it’s a myth. Why is denitrification so controversial? It is so easy and it makes your fish live longer. I have 8 tanks with stable N parameters of 0,0,0. It didn’t take months.. just 2-3 weeks after cycling. Denitrification is like a taboo subject on here. Or a magical thing only to be attained by a few experts.. or impossible! Shake that nitrate bottle for the 20th time and then go buy a new one.! Or only possible with loads of plants or a deep sand bed with a plenum. No it’s super easy! Often it happens by accident like in my husbands tank..

Here is one easy method ( there are others)

2.5 - 3 inches of natural gravel. There is a reason this depth was recommended on the bag. Hypoxic but not anoxic.
A good filter that doesn’t over-do flow. But you can start with high flow while cycling.
Some driftwood or fallen oak/ magnolia leaves for a carbon source
Cycle the tank the usual way and then get nitrates under 20 with water changes ( if you can’t because your tap has nitrates or whatever try nitrazorb for a week)
Don’t vacuum more than half the tank at a time leaving some gravel undisturbed. Then switch sides the next week. I only do every other week.
When you notice nitrate accumulating more slowly you can do smaller water changes and or space them out a little more and be careful not to disturb all the gravel when you do it.
You should notice nitrate accumulation rate dropping or even becoming negative.

Nitrates still not coming down?
Scatter some lava stones sold at Home Depot for grills on the bottom of the tank (don’t boil) to grow denitrifiers. If you start with this at the beginning it will go faster.

Still no ? .are you disturbing the deep parts of the gravel too much? Do you have too much flow in your tank? Try maximizing media in your filter while reducing flow or switch to (or supplement) your low flow filter with an air driven sponge or corner filter (make sure you seed it first in your tank or with used media) Always watch your parameters until things stabilize.

Has worked every time for me. Never had an ammonia spike. This also matches how fish were kept in the old days before we knew anything about cycling or bacteria. Back when fish lived forever.


Don’t believe me.? Try it with a small tank.

 

Most of my tanks read 0,0,0 too even though they're cycled. I like to pack my filters and keep a ton of plants in there and eventually I end up there. I still do my water changes but really if I stopped completely my tanks would probably be fine for months.

 

WOW! Thanks for that info! I always wondered...I could go a month (maybe longer, never chanced it) in my 150G with NO water change and still had 0/0/0. I had Cichlids used to hard slightly alkaline (8.0) water. Evaporation was minimal with well covered tanks, large canister filter and lots of aerators on the bottom. I've always kept lava rock as you mentioned in my tanks as a deterrent to Cichlid digging in much of the tank and used it to seed new tanks (excellent by the way-instant cycle if you move enough rock!). Had sand on the bottom, gravel, then lava rock. Left digging areas free of lava. The lava also prevented deep vacuuming. I did exactly what you said lol! Shook my nitrate solution, threw it away and bought new. Same results so I just thought, oh well, Fish happy? I'm happy!

 

I agree, but I use a different method. I put Seachem Matrix media in my filters. I've heard people who tried it say that it takes forever for the anaerobic bacteria to establish in them, but I find it takes very short time for a colony to establish--if one uses Seachem Stability to jump start the colony, which houses both aerobic and anaerobic bacteria. I also get 0, 0, 0. I still do weekly water changes, sometimes even do it twice a week. But when I'm out of town for 2 weeks or more, I'm confident in my filters doing their job.

 

With the random trouble people have with the aerobic part of the cycle, getting the rest of it is difficult. People are more afraid of deeper beds due to anecdotal stories that likely aren't true than they are of high nitrates.

While it isn't difficult, it also isn't simple to get a good colony. Mine is easy due to deep sand over dirt in a jungle tank. There aren't many people here setting up tanks like that. There also aren't many people wanting 2 to 3 inches of gravel. Not to mention people think more cleaning is better. I don't vacuum substrate ever, I only clean filters when they slow down, the only routine cleaning I do is algae removal. This isn't the way of most people though.

Then you have people smashing as much matrix or bio home as possible into their filters, thinking that is the best place for the anaerobic bb, and still don't get great results. This frustrates many people. This forum is more results based than science based. There are others that even after years of studying them, seem to be written by people with PhDs in aquaculture. Not to mention people like Tom Barr.

 

I wish I knew why you think its so easy. It's not in a bare bottom tank with guppies. But I'm gonna get more guppy grass. It's an ongoing process for me to find a balance between clean tanks AND enough fry hiding spots

 

I wish I knew why you think its so easy. It's not in a bare bottom tank with guppies. But I'm gonna get more guppy grass. It's an ongoing process for me to find a balance between clean tanks AND enough fry hiding spots

When you provide proper conditions it isn't very hard, but you will have trouble with achieving that in your setup.

 

I created that by accident. 3 layer 3-4" thick substrate, deep layers undisturbed, good water flow, airstones, driftwood, tight tank (little evaporation), a couple of years....

 

I created that by accident. 3 layer 3-4" thick substrate, deep layers undisturbed, good water flow, airstones, driftwood, tight tank (little evaporation), a couple of years....

Yep. Its not hard when you have a whole system setup. Trying to achieve it just inside a filter isn't easy.

 

I'm still working on this, but it's hard to accomplish with goldfish...

 

With the random trouble people have with the aerobic part of the cycle, getting the rest of it is difficult. People are more afraid of deeper beds due to anecdotal stories that likely aren't true than they are of high nitrates.

While it isn't difficult, it also isn't simple to get a good colony. Mine is easy due to deep sand over dirt in a jungle tank. There aren't many people here setting up tanks like that. There also aren't many people wanting 2 to 3 inches of gravel. Not to mention people think more cleaning is better. I don't vacuum substrate ever, I only clean filters when they slow down, the only routine cleaning I do is algae removal. This isn't the way of most people though.

Then you have people smashing as much matrix or bio home as possible into their filters, thinking that is the best place for the anaerobic bb, and still don't get great results. This frustrates many people. This forum is more results based than science based. There are others that even after years of studying them, seem to be written by people with PhDs in aquaculture. Not to mention people like Tom Barr.

But Wraithen, results, when there isn't the science or the possibility of using the science, do work. Filter media CAN harbor enough beneficial bacteria to maintain a tank, and water changes ARE necessary at some point even with dentrification. In Medicine, using the science you can with the knowledge or resources you have is called "evidence based practice". Bare bottom tanks have to use what they have. As do people with fish (like African Cichlids) that are constantly "plowing the tanks". So, guess what I'm saying is, it may not be the best approach or even feasible for many people.

 

I'm still working on this, but it's hard to accomplish with goldfish...

Understocking, dirted tanks with plants help. I'm reading up on walstads book. A lot of chemistry I have to slowly digest but its pretty good for understanding all this.

 

Understocking, dirted tanks with plants help. I'm reading up on walstads book. A lot of chemistry I have to slowly digest but its pretty good for understanding all this.

I didn't even have plants in my 150. Lots of tannin dumping wood though.

 

But Wraithen, results, when there isn't the science or the possibility of using the science, do work. Filter media CAN harbor enough beneficial bacteria to maintain a tank, and water changes ARE necessary at some point even with dentrification. In Medicine, using the science you can with the knowledge or resources you have is called "evidence based practice". Bare bottom tanks have to use what they have. As do people with fish (like African Cichlids) that are constantly "plowing the tanks". So, guess what I'm saying is, it may not be the best approach or even feasible for many people.

Oh! I didnt mean it to come off that way at all! I just meant that doing it inside a filter alone is a much more difficult way to do it! I wasn't trying to word it to convince someone they had to do it the way I stumbled into it on accident. Using that evidence based practice and then reading walstads book explains a lot of my observations.

 

Oh, well then. So, does it 'splain how that same thing happened in my totally unplanted tank? I still don't understand where those nitrates go if plants aren't eating them....

I did notice that the deeper, undisturbed substrate released trapped air bubbles if it was disturbed sometimes...methane?

 

Part of it is your substrate, part of it from the decay of the driftwood, part of it from the decay in your filter, some bacteria growing everywhere including your filter...

Did the bubbles smell? Theres really no telling. It all depends on what was eating and what was being eaten. I haven't gotten through to the bacteria roles in depth yet. Still trying to digest allelopathy right now. I shouldnt have passed chem 1 in high school so my brain is trying to understand everything with an understanding of pressures and magnetic and electrical charges and adapting that the chemistry. It doesn't work so well when she starts talking about interactions with phenol compounds.

 

I just did Organic chemistry in college. Just know about carbon chains and fatty acids...it's probably gas like methane from decomposition, because yes, it did stink. Only noticed a little but I didn't really disturb the deep substrate much at all. The fish and tank water did great! Guess I should have kept a fire extinguisher around. In case of a gas fire....

 

I just did Organic chemistry in college. Just know about carbon chains and fatty acids...it's probably gas like methane from decomposition, because yes, it did stink. Only noticed a little but I didn't really disturb the deep substrate much at all. The fish and tank water did great! Guess I should have kept a fire extinguisher around. In case of a gas fire....

How cool would that look! A fish tank on fire!

 

Lol, on fire. It wasn't possible in my overstocked 5 gallon, I was getting 20 ppm easy, with the filters gunking up fast. My new 65 however, has a deep soil and sand bed and a high capacity filter so it will probably get there.

 

I'm interested in how this works with plants. I'm given to understand that some nitrates is a good thing for medium/well planted tanks, but I'm also reading above that lots of plants can be a part of the 'recipe' for denitrification, ie 0 nitrates. Seems contradictory (or, more likely, I'm missing a piece of the groundwork LOL).
Also, what's the exit path for nitrogen gas from the system? I presume it's released by the microbes that make it directly into the water, then passes from the water to the air with circulation?
Is 2-3" of substrate a minimum for this process to happen? In something like a 10 gallon, that's a lot of the water volume taken away.
Can you get this to work by banking substrate up the back or a back corner of a tank? Eg 3" of sand in back left quadrant, less everywhere else?

 

So, a lot of plants will prefer ammonium. Ammonia can be problematic as the plant can't control the uptake, its free flowing through the cells. Nitrate actually never happens as the plant uses the ammonium and ammonia first. Then there is absorbing nitrate as needed as a nitrogen source.

The exit path I'm not entirely sure on atm, but I believe its during decomp. Speaking of which, this adds to your dissolved organic carbons in your tank which locks a bunch of things up. Humic compounds also will lock things away for you.
You don't need a deep sand bed. Typically, the dirted tank with a sand cap seems to work very well. Mine is 2 to 4 or 5 inches throughout. It seems like its more about overall surface area to hide in in low flow areas. The deeper the bed, the more this is allowed.

Jocelyn Adelman can probably school all this up much better than I.

 

Lol, on fire. It wasn't possible in my overstocked 5 gallon, I was getting 20 ppm easy, with the filters gunking up fast. My new 65 however, has a deep soil and sand bed and a high capacity filter so it will probably get there.

I did that recently fishwifery! Started with 7 guppys, ended up with over 200 in a 30 gallon! Was changing 75-80% water every other day, rinsing filters every day-Aaaaaaahh! Couldn't keep nitrates under 40! Finally found a fish store that took the lot of them. And then I could breathe...I did keep 5 males...

 

So much here not even sure what I should be responding to.

I have nitrates in my tap, also dose EI for my plants, continually bottom out on nitrates if they aren’t dosed... depending on the plants this might be ok, but my setups in particular are plant heavy and need supplements dosed to maintain their health...

0,0,0 tanks are fine... unfortunately MOST on here when asking about it aren’t older established tanks, nor are they using deeper appropriate beds, nor botanicals in their formulas. Also a 0/0/0 wouldn’t work for my light bioload heavy plant load... my tanks denitrify quite nicely, but my plants still need to be fed. Some I maintain a higher bioload and less ferts, others the opposite.

bitseriously you would be better off using something other then sand, slightly larger would work better

rainbowsprinkles best filter hands down is a mattenfilter, quite common in some countries, not so popular here in the US, covers the ‘bases’ you mentioned.

Momgoose56 still possible in a bare bottom depending on the decor... lots of wood/pours stones etc, plus age of the tank... barebottom would take longer, but has potential if enough “stuff” in it....

I remember when I once attempted to explain introducing mulm to a new tank ...personally believe this is where the myth adding WATER from an established tank came from, a mis read of the older using mulm... dirty stale water is nothing but dirty stale water... yet the sludge that’s in the substrate level is liquid ‘gold’

 

I've managed it accidentally in my lotl tank because of a massive quantity of plants and driftwood lol.

 

my tank is always 0,0,0. I keep water lettuce and anacharis to suck up nitrates. the TSS+ I used may have denitriying bacteria in it.
I used to believe the myth that 0,0,0 params always meant you're uncycled.

 

A tank that has less than 5 nitrates woykd have to be loafed with plants and few fish or only tiny fish. Most people are in this hobby to keep fish not water plants. Also, plants that have leaves above water and roots are much more efficient than rooted substrate or floating plants. Not many people have these type of plants that grow out if the water in nature an example is cat tails. Bamboo would be another possible example. But a few plants here and there and 20 guppies will never be able to balance 0 to 5 nitrates like nature does

 

Isn't the main question if one likes the nitrates to be 0? I don't actually.
There are times I just add them for plantgrowth.

 

I've always wanted 0 readings as a pond keeper and was until recently into planted tanks that they required nitrates. So I'm trying to get some lol and it's hard. The way my tank set up as a bog with water up through gravel substrate with bio falls filled with lava rock and the living top as well as a canister I can't get above 0 readings yet using thrive. If a tank is set up naturally in all aspects I can't see how you get nitrates. I have 5 big gold fish and about to crank up the nilocg thrive to see what it takes to get nitrates so I'm kind of reverse of 5he post but it's interesting.

 

I've always wanted 0 readings as a pond keeper and was until recently into planted tanks that they required nitrates. So I'm trying to get some lol and it's hard. The way my tank set up as a bog with water up through gravel substrate with bio falls filled with lava rock and the living top as well as a canister I can't get above 0 readings yet using thrive. If a tank is set up naturally in all aspects I can't see how you get nitrates. I have 5 big gold fish and about to crank up the nilocg thrive to see what it takes to get nitrates so I'm kind of reverse of 5he post but it's interesting.

View attachment 542420

Nice Jack.!

 

rainbowsprinkles scarface DoubleDutch Whitewolf So, I was wondering this. My nitrates don't seem to go above 5ppm. I attribute it to my frogbit and pothos. With that said, it still seems water changes are critical with the group here at FL. What does the water changes do if nitrates aren't the issue? Is there a test for it? I hear these internet legends about it not being necessary to do water changes.

Also, just so everyone knows, 0 ammonia is almost impossible to obtain. Most people say 0 ammonia, but it is there <0.25ppm. Don't believe me? Take some Distilled water and test it and take some tank water and test it. You'll see the difference. <0.25 is what people often call 0 it seems.

Edit: after reading this more carefully, I wonder if I gravel vac to much. I'm a clean freak if you understand. I'll switch to 50% only at a time.

 

rainbowsprinkles scarface DoubleDutch Whitewolf So, I was wondering this. My nitrates don't seem to go above 5ppm. I attribute it to my frogbit and pothos. With that said, it still seems water changes are critical with the group here at FL. What does the water changes do if nitrates aren't the issue? Is there a test for it? I hear these internet legends about it not being necessary to do water changes.

Also, just so everyone knows, 0 ammonia is almost impossible to obtain. Most people say 0 ammonia, but it is there <0.25ppm. Don't believe me? Take some Distilled water and test it and take some tank water and test it. You'll see the difference. <0.25 is what people often call 0 it seems.

Edit: after reading this more carefully, I wonder if I gravel vac to much. I'm a clean freak if you understand. I'll switch to 50% only at a time.

Water changes are still recommended to add used up minerals back to the water and to remove excess of the unused minerals that would accumulate by simply topping off.

 

Water changes are still recommended to add used up minerals back to the water and to remove excess of the unused minerals that would accumulate by simply topping off.

This. You see it quickly in cycling tanks with lower kg levels. Just the cycle alone eats up a good amount of minerals. There are also things you can't test for that need to be removed. Various hormones, not harmful, but not good for a healthy stock either, excessive dissolved solids that you don't want. Also, if you aren't stopping off with distilled or rodI water, you are building levels of dissolved solids. Plants change the game a bit, but planted tanks get water changed either to replenish what's in the water, or just to reset levels.

The salt world seems to keep a better level on everything. They test for more and would rather replace what's missing since that's the easiest and cheapest route. For fresh though, we do more frequent, larger water changes. I'm down to once a month or so, but I'm constantly struggling to have enough macros in my tank for plants as it is. You think fish eat a lot, wait till you have a mother sword that decides its happy for a bit!

 

rainbowsprinkles scarface DoubleDutch Whitewolf So, I was wondering this. My nitrates don't seem to go above 5ppm. I attribute it to my frogbit and pothos. With that said, it still seems water changes are critical with the group here at FL. What does the water changes do if nitrates aren't the issue? Is there a test for it? I hear these internet legends about it not being necessary to do water changes.

Also, just so everyone knows, 0 ammonia is almost impossible to obtain. Most people say 0 ammonia, but it is there <0.25ppm. Don't believe me? Take some Distilled water and test it and take some tank water and test it. You'll see the difference. <0.25 is what people often call 0 it seems.

Edit: after reading this more carefully, I wonder if I gravel vac to much. I'm a clean freak if you understand. I'll switch to 50% only at a time.

0 ammonia is very attainable it's the test kit that is faulty to .25

 

Neat, I was wondering why my 10 gallon has always had 0,0,0 readings. I've been super busy the past few months and have probably done a grand total of two or three 25% water changes since December. I know I'm still supposed to do water changes to replenish minerals, but quite honestly I haven't gotten around to it; my other tanks have needed more attention. My filter quit last month (for the second time!! gosh darn power surges... my fault for not having a protector) and I decided not to replace it. So now the ONLY tech in/on the tank is the light. Readings are still 0,0,0 and my cherry shrimp, CPDs, killifish and one nerite snail are thriving in there with zero mechanical filtration, zero aeration, and no heater (all inhabitants are cold-tolerating animals). In fact I saw a few CPD fry a few weeks ago but I believe they got eaten. Very happy to see the whole system (fish, inverts, plants, water chemistry) thriving with minimal attention and tech.

 

Neat, I was wondering why my 10 gallon has always had 0,0,0 readings. I've been super busy the past few months and have probably done a grand total of two or three 25% water changes since December. I know I'm still supposed to do water changes to replenish minerals, but quite honestly I haven't gotten around to it; my other tanks have needed more attention. My filter quit last month (for the second time!! gosh darn power surges... my fault for not having a protector) and I decided not to replace it. So now the ONLY tech in/on the tank is the light. Readings are still 0,0,0 and my cherry shrimp, CPDs, killifish and one nerite snail are thriving in there with zero mechanical filtration, zero aeration, and no heater (all inhabitants are cold-tolerating animals). In fact I saw a few CPD fry a few weeks ago but I believe they got eaten. Very happy to see the whole system (fish, inverts, plants, water chemistry) thriving with minimal attention and tech.

You may enjoy the book diana walstad published a long time back. She researches a tank with plants and fish and nothing else. It's a fun experiment, but the algae in her method would drive me nuts!

 

I just recently achieved 0,0,0 in my unplanted tank that has only 1.5" of sand... with goldfish... and a canister filter... that has only been set up since December! Sounds impossible! Here's the thread I made about it:

I've Done It, Perfect Cycle 75 Gallon Tank - | Cleaning and Maintenance 403644

I think the Biohome MinI really helped. The sand gets stirred up a lot by one of the fish, and I rearrange a lot. But it wasn't that hard and I was amazed it happened so fast, as it sounded like a bizarre holy grail myth that was a fool's errand at best, and likely to kill your fish at worst.

 

You may enjoy the book diana walstad published a long time back. She researches a tank with plants and fish and nothing else. It's a fun experiment, but the algae in her method would drive me nuts!

I've heard much about it, but haven't had the time to pick it up and read it. I definitely love the concept, especially as such a busy person who still wants to enjoy a thriving planted tank. My tank does have a considerable amount of algae. The typical surface-growing algae gets chomped down very well by my nerite snail. I have hair algae that's decided to grow out of my moss and I've needed to physically remove a lot of it but then realized it's growing so vigorously only because the moss is almost reaching the surface now, which means it's getting more light/the algae is getting more light. I trimmed the moss down by about 1/2 and now that it's a good four or five inches away from the surface again, the hair algae is dying off. My rooted plants love the low-tech tank too (it's dirted with a sand cap). Such a simple set-up and very self-maintaining.

 

Sorry about my negative sounding rant about plants. I just wish they were less pricey, and my hard water means they don't do very well. I have used fake plants for most of the time in my hobby because they are cheap and never die. I sometimes collect plants out of the lake and ponds near me because well that's, free and pond plants are hardy. It bites that they want like $9.99 for a aquarium water plant. They should all be cheaper.

 

Sorry about my negative sounding rant about plants. I just wish they were less pricey, and my hard water means they don't do very well. I have used fake plants for most of the time in my hobby because they are cheap and never die. I sometimes collect plants out of the lake and ponds near me because well that's, free and pond plants are hardy. It bites that they want like $9.99 for a aquarium water plant. They should all be cheaper.

Check with clubs. You can usually find plants for cheaper. I recently scored 8 crypt lutea in a single pot. Lfs told me it was 1 plant and that he had it for a couple months. Once I let it hang out a few days in my tank and took apart the rock wool, I discovered this crypt had made a bunch of babies in the pot.

For hard water, crypts, swords, ludwigia, vals, lobelis cardinal plants, wisteria, anubias and lotus bulbs seems to work well for me. I have a ph of 8 to 8.2 so I know your struggle. One of my lfs has an 11 foot tank the plants go it that is half ro half local water. I keep forgetting that and wonder why plants live there for a month and then die after a week in my tank. Don't forget that you're buying a root system, not leaves. I had a frozen flamingo crypt arrive in the mail. I waited for a baby leaf to sprout and then clipped all the old leaves off. The only reason I waited that long was so I could know where the plant was if it wasn't going to recover.

 

Yes your basically buying the roots because plants don't do well with being shipped and massive water chemistry fluctuations. Well for my situation wraithen I prefer floating plants. Bare bottom tubs and later on tanks. Right now duckweed and I bought some water lettuce. Thinking about investing in some other floating plants that are hardy like frogbit. Just prefer plants at the surface because with guppies I usually do a bare tank. Those plants are also hardy and are able to suck a lot of nitrates out of the water because they rely on their roots and the outside air and bright light at the surface, not just being water bound and lower light. More function plants like water lettuce and frogbit is gonna be my focus. Hopefully, I can bring them in to the house this year and acclimate them to winter without the dieback I had last winter.