High nitrates from water change neglect. What to do?

Hi All, I'm a bad fishkeeper.

I have a 72g tank, had it running for like a decade. fish act and appear fine, water is clear, Ammonia and Nitrites are always zero.

However I have a dirty secret. somewhere around 2014-2015 I trickled off on water changes and just did top offs, tests weren't showing much change at the time and after a while I stopped testing also.
About a month ago, I decided "I should really test this". Nitrates are pegged on the API test kit and two different brands of test strips ( I wanted to be sure) the APi test is beyond 160ppm, on the other test strips bought from Amazon, they color up to 250-500ppm range on the chart with the strips (I don't want to think it's really that high!)

I did a 50% water change, it don't seem to even phase any of the tests. I'm still way up there in what must be the 200-300ppm range. Am I destined at this point to keep doing 50% over and over until it comes down as the solution?

I have a 150 wet/dry filter box underneath as my filter could I in theory drain the tank to the substrate, but leave the couple gallons (5-10g, it's a 20g sump at max volume.) in the wet/dry and start with new water and keep my biological for ammonia and nitrites between the substrate and filter, or would it mean having to start a new cycle if I drained the tank 90+%? I feel I need to get it back under control but don't want to spend 6 years of water changing to do it. Again, though the water is clear, the fish act normal and were adults before this ever happened, but I know it's not good
So wondering IF I do a darn near full change in one shot, will I lose my cycle with this system?
If I do like a 90%+ water change bring the water in the tank right down to the substrate, and the few gallons in the sump, I feel like if I'm at 250-300ppm still, it should get me down to the 25-30ppm range give or take in a single afternoon. maybe come back with a 20% vacuum a week later to clean the substrate out then, a week or so later then clean the filter floss? I think it COULD work, but not sure. if it took a month + to do it with smaller water changes, maybe just starting a new cycle is a similar option also as far as length of time.....

I don't ever intend on being this neglectful again with it. but looking for advice on how to proceed to get it way down. I'm not sure what to do.

*edit* yikes I just had a thought, I can't go this fast because the fish are all acclimated to the really high nitrates right? I'd need to be prepared to lose the fish if I do something that drastic even if it did keep the cycle.........

 

You will want to do it slowly. The fish are used to the high nitrates. A full tank water change will shock them too much. It won't affect your cycle changing water.

 

Do you have live plants? Fast growers will suck up nitrates. Try putting some pothos vine clippings in the water.

 

Hi SparkyJones

I believe anyone could be confused by what “ slowly “ means.

You can change some water every 4 hours. That is still slowly . Changing 45% of the water in the morning and again in the afternoon is still slowly.

The cycle is bacteria that live ON hard surfaces.
You should not clean hard surfaces more than a little each week. Cleaning 1/3 of the gravel each week is often the advice given . Cleaning only part of the filter on another week would be safer .

Changing 45% of the water every day may be convenient for the human.?

 

Do you have live plants? Fast growers will suck up nitrates. Try putting some pothos vine clippings in the water.

I don't have plants or algae at all for a long time, when I did have some algae it was the brown (silica algae I think) one that is like a powder dust when you wipe it off the glass or rocks but it's been many years since that happened, around when I cycled the tank. Could plants really use up all of that nitrate relatively quickly or not get where I need to be for a couple years?

also Pothos, like the ivy looking plant at Home depot? I thought that was a land plant?

 

Pothos is a land plant, but it is great at sucking up nitrates when only it's roots are submerged in the water. Floater plants also do the same thing.

 

Old tank syndrome with prolonged high nitrates and phosphates results in changes to the water chemistry with the pH dropping. Do a search on old tank syndrome. Small water changes 10% - 15% daily are recommended with monitoring of ammonia and pH. If the ammonia should rapidly increase, skip water changes for a few days and add an ammonia reducing agent. You don't want the pH to increase more than 0.3 units a day

 

What cdwag29 said. You can get a pot of pothos at home depot. Look up pothos in fish tank to see how to prepare it. I think it would be beneficial if you added a lot of plants. Go for some floating plants as well, like duckweed, salvinia, water lettuce, or frogbit. A stem plant like hornwort would also be great, it can just be left floating throughout the tank.
Plants will not immediately solve the issue, but will help, and your fish will enjoy them.

 

Agreed. I had "high" nitrates for a while, and after getting duckweed and hornwort my nitrate levels dropped so much I can't even tell if they read as 0 ppm or 5 ppm. Both can get out of hand though, so prepare to have an abundance.

 

Hi SparkyJones

I believe anyone could be confused by what “ slowly “ means.

You can change some water every 4 hours. That is still slowly . Changing 45% of the water in the morning and again in the afternoon is still slowly.

The cycle is bacteria that live ON hard surfaces.
You should not clean hard surfaces more than a little each week. Cleaning 1/3 of the gravel each week is often the advice given . Cleaning only part of the filter on another week would be safer .

Changing 45% of the water every day may be convenient for the human.?

Thank you. yeah, it's all subjective lol. I test the water for nitrate, I'd assume the high reading is in the water, However, there's got to be high nitrate in the substrate also, and well just about everywhere the water is also including the filter. the thing is I don't want to lose the cycle if it can be avoided, And I REALLY don't want to lose the fish lowering the nitrates too quickly. The thing is "too quickly" and "slowly" are subjective.
easy enough to run a siphon with the hose out the front door and in an hour drop it down to the substrate,and then run the hose to fill it for a half hour, but if that kills the fish or crashes the cycle it was a bad idea to do it, clearly.
If I do a 50% on day one, and it manages to drop nitrate to 150ppm (not saying it will, a month ago it didn't but IF) and then doing 20 gallons by 5 gallon buckets and a step ladder, every day for 7 days, I could break the 40ppm mark. at a week and spend another week of 20% changes to get down under 20ppm.

And if it doesn't get me to 150ppm, another 50% change or two until i get there adding some more days to the time line.... The fish tolerated the first 50% change a month ago well with no losses or even a struggle, but it didn't lower anything as far as the tests were concerned either.

I'm not against water changes anymore really, I do it consistently on my two smaller tanks. but for the big tank just a lot of work and, just not wanting to do it previously, and I got into the habit on the smaller tanks and wanting to bring the big one back in order.

I "feel like" after that first water change of 50%, I could do a 90% and likely still be topping 40ppm, if I had to do 10-20% a day for a week from there,2 or 4 buckets out, 2 or 4 buckets in. it's when it's 14 trips to do a 50%, it's a mission.

I dunno, I guess I'll never get anywhere worrying about it and doing nothing at all. I'll do what I can daily with time I have available, between 10-50% each day and see where it gets me in a week I guess. to move a mountain, do it one stone at a time.

 

I could do a 90%

I would stay away from this myself.

I dunno, I guess I'll never get anywhere worrying about it and doing nothing at all. I'll do what I can daily with time I have available, between 10-50% each day and see where it gets me in a week I guess. to move a mountain, do it one stone at a time.

This is so much a better plan!

 

You could fill up your testube with half tank water half fresh water to see of your nitrates budge off max. (Then double the reading to get tank levels.) That way you might be able to see impacts of water changes a little better if you can get a read on your nitrates.

 

Should try to drip the water back if possible. What fish do you have?

 

Go for some floating plants as well, like duckweed, salvinia, water lettuce, or frogbit.

Only thing about duckweed is well... duckweed. It's not gonna go away once you put it in your tank. But floaters really do help clean up nitrates. If the tank isn't planted I'd definitely look into planting it. You can use easy plants such as Anubias and Java Ferns, they SHOULD NOT be planted into the substrate however. Other than that and they're pretty hardy (you might see the java fern melt a bit, that's just a standard growing process). If not, you could look into pearl weed, as it grows pretty fast. The world of plants is pretty amazing.

 

Should try to drip the water back if possible. What fish do you have?

Some angelfish, some gouramis and kissing gouramis.
I had given that some thought to remove the fish with tank water then drip acclimate after the big water change before returning them to the new water, but if I lose the cycle we could get stuck in a bad spot.

 

Some angelfish, some gouramis and kissing gouramis.
I had given that some thought to remove the fish with tank water then drip acclimate after the big water change before returning them to the new water, but if I lose the cycle we could get stuck in a bad spot.

You wont lose the cycle its more to avoid parameter shocks like rising pH which can quickly turn ammonia toxic

I wouldnt take the fish out, but rather avoid stressing them as much as possible.

Although dripping water into 72g can be very tedious.... I use a 60g container and a pump connected to airline tubing to pump water back which ill run for an hour or so

 

Ok pictures will help. How long have you had the fish? I’m surprised the 50% water change didn’t shock them. Have you checked your tap water?
Yes old tank syndrome! How big are the fish? I’m thinking your substrate is full of mulm. So you’ve got to vacuum it out. That’s where the nitrate it coming from. You change the water but it just comes out of the substrate and probably the filter. Is there mulm under the ball pit in wet/dry?? Again pics will help. What I would do now is remove the fish into a smaller tank filled with the bigger tanks water. How many fish?? Filter this tank with some of the media from the wet/dry. Change the water daily in this tank by 30% till the nitrate is down to 5%. Next clean up the other tank. May have to remove all the gravel and replace (probably the quickest and easiest way). Clean down all the walls and whatever else is in there. Next clean out the filter. While your cleaning out the tank you can put a heater and sponge filter in the wet/dry it keep it circulating. What type of pump in wet/dry? I know lots of questions. I’ve got a few wet/drys running and once I’ve got more info I’ll have more ideas.

 

If your test strips are showing at the maximum level, it is quite possible that the actual concentration is several times that amount. If you did a 50% water change and the nitrate test did not decrease, then it is quite likely you are well above the maximum test level.

If you want to know the actual nitrate value, you can mix 1 teaspoon of aquarium water with 9 teaspoons (3 Tablespoons) of tap water (purified water would be even better). Then dip your test strip into the diluted sample. Read the result and the multiply that result by 10X to get the actual value. You might be shocked.

You cannot undo years of neglect, but you can do better from now on. Do not do something drastic, but just resume the maintenance practices you know to be suitable. Since you have a rather large tank, you might try changing 20 - 25 gallons twice a week (30%) until the nitrate level gets down below 20 ppm. Then go to a once per week schedule.

 

Ok pictures will help. How long have you had the fish? I’m surprised the 50% water change didn’t shock them. Have you checked your tap water?
Yes old tank syndrome! How big are the fish? I’m thinking your substrate is full of mulm. So you’ve got to vacuum it out. That’s where the nitrate it coming from. You change the water but it just comes out of the substrate and probably the filter. Is there mulm under the ball pit in wet/dry?? Again pics will help. What I would do now is remove the fish into a smaller tank filled with the bigger tanks water. How many fish?? Filter this tank with some of the media from the wet/dry. Change the water daily in this tank by 30% till the nitrate is down to 5%. Next clean up the other tank. May have to remove all the gravel and replace (probably the quickest and easiest way). Clean down all the walls and whatever else is in there. Next clean out the filter. While your cleaning out the tank you can put a heater and sponge filter in the wet/dry it keep it circulating. What type of pump in wet/dry? I know lots of questions. I’ve got a few wet/drys running and once I’ve got more info I’ll have more ideas.

One thing about vacuuming substrate - if there is a thick substrate layer in this neglected tank, thorough vacuuming could release toxic hydrogen sulfide gas. If this happens, the fish will suddenly die.

 

Here is the tank. The kissing gouramis are 10-12 years and been there the longest, the smaller gouramis are about 5 years, the angels are 3 years there.

I don't have live plants at all, substrate is riverstone from home depot and nothing else some petrified wood chunks and some broken slate rock I got for free and. Then a decoration I've had since forever a little rock structure thing with two holes. A couple plastic plants.

My tap water is fine I don't have the issue with the smaller tanks, just this one and I'm sure it's because I neglected water changes forever out of laziness, it being more of a chore than a 10 or 20 gallon.

If there is a mulm I didn't see it. There is a fine beige dust, like fine sand down in the substrate that kicks up when I vacuumed and settles again in a couple hours. It's also down in the wet dry to a small extent very small a light layer makes it past the filter floss.
Honestly I don't know about the pump in the wet/dry for sure... 600-700 gallons per hour I think? I've had it a long time and it functions well enough to return the water without being completely submerged, Even at max flow rate from the prefilter box up top. It is a 72g, the wet/dry is a 150 and double sized for the tank I guess. I got it 2nd hand back when I bought the tank in the middle 90s. If that's right it's like a half a liter per second for flow, not sure if it's too little or too much but it seems to circulate fine without blowing fish around the angels have no issues with it.

I liked the test dilution method suggested. I took a test it's the test strip picture 1. My nitrites tested white but the nitrate zone bled into it by the time I took the picture.
2nd picture is a dilution 90 ml of tapwater, 10 ml of tank water, so test result at 10% tankwater.

Also I just realized the pH is way down, and and total hardness is up?

Last test picture attached is straight tap water and nothing else.

At this point after the dilution test I believe there's light at the end of the tunnel, likely the 50% change I did a month ago cut it in half, and it was near 1000ppm nitrate? I dunno. Seems crazy. Lol but like I said (and I'm embarrassed to admit) it's like 6 years with no water change....

I should probably also mention that I do use seachem prime religiously any time I add water to any tank and use 4 drops per gallon instead of the 3 the bottle says to use. Just in case that does something.

 

Here is the tank. The kissing gouramis are 10-12 years and been there the longest, the smaller gouramis are about 5 years, the angels are 3 years there.

I don't have live plants at all, substrate is riverstone from home depot and nothing else some petrified wood chunks and some broken slate rock I got for free and. Then a decoration I've had since forever a little rock structure thing with two holes. A couple plastic plants.

My tap water is fine I don't have the issue with the smaller tanks, just this one and I'm sure it's because I neglected water changes forever out of laziness, it being more of a chore than a 10 or 20 gallon.

If there is a mulm I didn't see it. There is a fine beige dust, like fine sand down in the substrate that kicks up when I vacuumed and settles again in a couple hours. It's also down in the wet dry to a small extent very small a light layer makes it past the filter floss.
Honestly I don't know about the pump in the wet/dry for sure... 600-700 gallons per hour I think? I've had it a long time and it functions well enough to return the water without being completely submerged, Even at max flow rate from the prefilter box up top. It is a 72g, the wet/dry is a 150 and double sized for the tank I guess. I got it 2nd hand back when I bought the tank in the middle 90s. If that's right it's like a half a liter per second for flow, not sure if it's too little or too much but it seems to circulate fine without blowing fish around the angels have no issues with it.

I liked the test dilution method suggested. I took a test it's the test strip picture 1. My nitrites tested white but the nitrate zone bled into it by the time I took the picture.
2nd picture is a dilution 90 ml of tapwater, 10 ml of tank water, so test result at 10% tankwater.

Also I just realized the pH is way down, and and total hardness is up?

Last test picture attached is straight tap water and nothing else.

At this point after the dilution test I believe there's light at the end of the tunnel, likely the 50% change I did a month ago cut it in half, and it was near 1000ppm nitrate? I dunno. Seems crazy. Lol but like I said (and I'm embarrassed to admit) it's like 6 years with no water change....

I should probably also mention that I do use seachem prime religiously any time I add water to any tank and use 4 drops per gallon instead of the 3 the bottle says to use. Just in case that does something.

Please don't overdose the prime, prime also removes oxygen from the water which will cause serious problems to fish in the long term

 

One thing about vacuuming substrate - if there is a thick substrate layer in this neglected tank, thorough vacuuming could release toxic hydrogen sulfide gas. If this happens, the fish will suddenly die.

Yes that’s a reason I said to remove fish first .

Please don't overdose the prime, prime also removes oxygen from the water which will cause serious problems to fish in the long term

I really don’t think you can overdose prime.

Ph is down from OTS. Fish have adapted to the water. This happens over time. On a side note . This kind of proves nitrates are harmless to fish and removing nitrates is just a manufactures plow to sell product . Truth in this thread . Ok back on topic. Not a great pic of the wet/dry not a lot of fish in the tank. Fish all look fine. Yes your overfiltering the tank but it doesn’t look like there’s a lot of media. Are there any sponges in the filter? Just to refresh myself : the problem is you noticed high nitrates? Your fish are fine.

 

Yes that’s a reason I said to remove fish first .

I really don’t think you can overdose prime.

Ph is down from OTS. Fish have adapted to the water. This happens over time. On a side note . This kind of proves nitrates are harmless to fish and removing nitrates is just a manufactures plow to sell product . Truth in this thread . Ok back on topic. Not a great pic of the wet/dry not a lot of fish in the tank. Fish all look fine. Yes your overfiltering the tank but it doesn’t look like there’s a lot of media. Are there any sponges in the filter? Just to refresh myself : the problem is you noticed high nitrates? Your fish are fine.

Yes. You can overdose prime and deplete oxygen in the water temporarily in the process if you do, BUT it takes A LOT of prime to do it, not just an extra drop per gallon.

I wouldn't say nitrates are harmless necessarily, I'm pretty sure if I attempted to introduce any new fish they would die in the next 12 hours tops, unable to adjust go into shock and die.

I have a prefilter sponge tube on the downpipe to the wet/dry that catches food poop and skim that I clean 2x a week. In the wet/dry is a cotton floss mat above the bio things(not balls), that catches anything the sponge prefilter doesn't. The floss gets changed every 30 days or so, sometimes 60 days. The W/D is meant for a 150 size tank, I'd think the media is double the amount a 75 W/D should have.


Yeah. The problem is I noticed really high nitrate on on test, did a 50% w/c and still just as high.. I'd like to add fish or do something else with the tank maybe use it as a grow out, not sure what yet, but I'm darn sure without making a test sacrifice to prove it, that I can't add fish the way it is without them dying between the pH and the nitrates.

 

IIRC studies on nitrate toxicity have shown immediate effects (ie under 24hrs) at ~1000ppm and long term effects (ie a month) at ~50ppm. Not many longer studies but I assume if time is extended then we would see effects from even lower concentrations.

Anyways I still suggest slow water changes... How you can achieve that is a challenge that needs to be solved....

Not sure what sump 150 means, does that mean 150 gallons of sump?

 

If you have a wet/dry filter in a sump, they are often accused of being nitrate factories. They are VERY efficient at converting ammonia to nitrite and nitrite to nitrate, but they cannot remove nitrates. Thus, nitrate levels will continue to increase if you neglect water changes.

There are many different thoughts on water change percentages and intervals. For those with smaller tanks, changing 50% of the water each week is quite doable. For larger thanks, water changes are more difficult, but even changing of the water once a month would be helpful. However, until you get the nitrate level under control, you are going to need to do water changes more frequently than once a month.

 

IIRC studies on nitrate toxicity have shown immediate effects (ie under 24hrs) at ~1000ppm and long term effects (ie a month) at ~50ppm. Not many longer studies but I assume if time is extended then we would see effects from even lower concentrations.

Anyways I still suggest slow water changes... How you can achieve that is a challenge that needs to be solved....

Not sure what sump 150 means, does that mean 150 gallons of sump?

Well this tank contradicts that study. And you read this often. People who never change water. The fish look fine. Some having been there for the last 7 yrs. again I never bought into the nitrate’s are going to kill your fish thing. Yes most new fish don’t stand a chance entering that tank. But the op has added fish that have made the transition. The 150 means the wet/dry is made for a 150g tank. Now this isn’t necessarily true with this tank. The pump isn’t move enough water to filter a 150 at 600gph. But it’s still plenty for a 75g.
Op if that is the original pump you are one lucky guy. I suggest a new dc pump that can move up to 1200gph. These pumps are adjustable a cheap to run. Cheaper at half speed and there’s always more if you want it. Like I said if you want to turn that around your best bet is what I said earlier. That tank just needs to be cleaned out. In a smaller tank the existing fish will be fine and the amount of water your changing much less. The main tank after removing the gravel and replacing it. Refilling it and letting it run on the wet/dry for 24hrs or so you can introduce new fish while your old guys are reaclimating to cleaner water. Than slowly move them back into the 75. 2 at a time every 48hrs. Once alls back change the water weekly. I love wet/drys! But I change my water a lot. Fish love clean water. People get lazy and don’t want to do it. Just dedicate 1hr a week to change 50% and you’ll be fine.

 

Well to be honest, the tips from sunflower420 and RayClem about half test and dilute test gave me a good idea on where the nitrates really are and I did a 20% waterchange today. Not bad, but not good either, took an hour. doing 3 gallons is a quick 10 min job on a 20g or 10g, doing that 5x is an hour. but I suppose it could be worse and I can do this.
I'm not going to test again for a while so I don't get discouraged, I just don't want to know.
I'll do 20% 2x a week, every 3rd day or so and see where I am in a month. With no nitrates added I could be down to 60ppm in 10 water changes and a month time. 12 changes to get under 40ppm, and somewhere around 15 changes to get some wiggle room. Considering the pH is down below 5, I decided to just take it slow and not cramp the fish up in the 20g.
Thank you all for the input, it all helped a lot to determine the best way for the fish to adjust back and just doing the waterchanges in bigger baby steps seems the best path forward. Maybe when I get down to 100ppm and the pH back up I'll try a 50% to speed it up at that point... I'll see when the time comes.

If anything I might look into a larger diameter and longer siphon and just run it out the door, draining is the time waster. Refilling 15 gallons is quick, taking it out takes all the time.

88ssinit, I appreciate the recommendation on the 1200gph pump. And when this one breaks I'll surely be looking into one. As it stands, the one I have is still working and does a good enough job. It's the one I got with the wet/dry, but I did clean everything up and put it all away for a good 10-15 years before setting it up again, basically just for the kissing gouramis. I had the pair in a 20g and it was just too darn small, theyd get spooked and slam into the glass and couldn't really move in there so I dusted it off set it up and moved them over. Then added the others along the way. I don't think the tank was as bad as it is when they came in or the gouramis, it was probably a bit high for the angels when I put them in by then. I got the tank in mid 1990s and did Malawi Peacock African cichlids for a decade, put it away for a decade and set it up again maybe 10 years ago feeling bad for the kissers.
I put it away because it was a lot of work, I just didn't think the kissers were gonna get as big as they did or live as long as they do when I got em, I learned that later.

I am a fan of wet/dry filters also at least for bigger tanks, but I'm a bigger fan of an air driven sponge filter on a smaller tank, so cheap so simple so easy. I HATE the hang on back filters, and not a fan of the canister filters. But they all have their merits and negatives.

Maybe I get matrix or pond matrix after reading up on it and bag it and stick it in the wet/dry after I get the nitrates down in order to cut back on water changes once I'm at a good point again...

 

Well this tank contradicts that study. And you read this often. People who never change water. The fish look fine. Some having been there for the last 7 yrs. again I never bought into the nitrate’s are going to kill your fish thing. Yes most new fish don’t stand a chance entering that tank. But the op has added fish that have made the transition. The 150 means the wet/dry is made for a 150g tank. Now this isn’t necessarily true with this tank. The pump isn’t move enough water to filter a 150 at 600gph. But it’s still plenty for a 75g.
Op if that is the original pump you are one lucky guy. I suggest a new dc pump that can move up to 1200gph. These pumps are adjustable a cheap to run. Cheaper at half speed and there’s always more if you want it. Like I said if you want to turn that around your best bet is what I said earlier. That tank just needs to be cleaned out. In a smaller tank the existing fish will be fine and the amount of water your changing much less. The main tank after removing the gravel and replacing it. Refilling it and letting it run on the wet/dry for 24hrs or so you can introduce new fish while your old guys are reaclimating to cleaner water. Than slowly move them back into the 75. 2 at a time every 48hrs. Once alls back change the water weekly. I love wet/drys! But I change my water a lot. Fish love clean water. People get lazy and don’t want to do it. Just dedicate 1hr a week to change 50% and you’ll be fine.

This tank is not a controlled experiment and it is a small sample size, so it doesn't really have any relevance to the study. The OP is using test strips which are not precise anyways.

Those toxicity studies also look at expected values for mortality, IE how much concentration to achieve 50% mortality within a period of time. So it is not a guarantee that those concentrations will always kill your fish.

It's a big mistake to think that our 1 tank can contradict the results of a controlled scientific experiment...

 

This tank is not a controlled experiment and it is a small sample size, so it doesn't really have any relevance to the study. The OP is using test strips which are not precise anyways.

Those toxicity studies also look at expected values for mortality, IE how much concentration to achieve 50% mortality within a period of time. So it is not a guarantee that those concentrations will always kill your fish.

It's a big mistake to think that our 1 tank can contradict the results of a controlled scientific experiment...

Lol I’m with you! A controlled experiment is much more factual than reality!! . Many people run their tank like the op. As long as your not adding new fish the existing fish do fine. Not all fish owners are on the net. Ask your coworkers if any own tanks. You’ll be surprised. Got about 8 guys on my job that own tanks and never even heard of a test kit. Most have had the same fish for 5 plus years and only top off the water. Fish can adapt to high nitrate water and survive. The API master kit didn’t even come with a nitrate test in 2003.

 

Agreed, high nitrates are just not very toxic. I did the lazy care thing on a tank for a couple of years. Only changed water (about 30%) every 3-4 months. Not as extreme as the OP's case, but once I finally tested for nitrates it did peg 160 on the API test kit. All the fish were fine. To bring it down I did the same 30% WC/Gravel vac every week. It took a while but no shock and the fish were fine. My advice is don't do anything drastic.

 

When doing water changes remember that nitrates might not drop as quickly as you anticipate. As you feed your fish and they excrete waste, your filter will be producing more nitrates. Once nitrates get down below 40 ppm, reduce your water change frequency to keep them below that level.

 

Well I did 20% water changes daily since Saturday, honestly, nothing has changed and I fear i'd be right here in another month of it, so I decided to read around on "old tank syndrome". I found this article that chose a different way to fix the issue, why it happened, and what's happening, and the reasoning behind doing it the way they recommend vs doing it slowly, and in my circumstances, this is the recommendation I will use likely this weekend and then acclimate the fish after the near 100% water change. Fingers crossed.

 

Well I did 20% water changes daily since Saturday, honestly, nothing has changed and I fear i'd be right here in another month of it, so I decided to read around on "old tank syndrome". I found this article that chose a different way to fix the issue, why it happened, and what's happening, and the reasoning behind doing it the way they recommend vs doing it slowly, and in my circumstances, this is the recommendation I will use likely this weekend and then acclimate the fish after the near 100% water change. Fingers crossed.


and then the info above that doesn't link. I found it reasonable and logical.

That's a banned link on here, but I don't think old tank syndrome has a strict definition, it can be many things...and I dont think your tank has high ammonia.

Personally I would still use a drip system for water changes in this scenario

 

no it doesn't. I've got zero ammonia and zero nitrates, but it's been years, possible I've got a colony of archaea in the biological filter breaking down the Ammonia now. and if they get killed off, then the ammonia spikes and I have to build for a new colony of higher pH nitrifiers. it would be cycling all over again.
I agree I will take the fish out to a bin with a sponge filter and tank water and drip acclimate slow after the 100%. change, before sticking them back into the tank.

It makes the most sense overall. I'm dealing with a pretty big problem, and if it's as bad as I think it is, when I do gain ground on it, it's going to cause problems with the water parameters along the way and kill off the low pH bacteria colonies and I'd be starting over on a cycle anyways.

a month to cycle, or a month to change water and whatever might come with that along the way and possibly cycling over again anyways..... probably the month to cycle if it comes to that, I've got sponge filters to kick start off of once I've got water conditions the bacteria can live in. i'd rather get it sorted out quickly and deal with starting a new cycle. than doing what I've been doing. the worst thing about what I've done for the last 5 days is I've done 5 20% water changes and the pH hasn't budged from below 5. and out of the tap it's about 7.8-8.0. I'm not gaining ground at all, and when gaining on it does happen, there's going to be issues with imbalances that I believe will also distress the fish.

 

no it doesn't. I've got zero ammonia and zero nitrates, but it's been years, possible I've got a colony of archaea in the biological filter breaking down the Ammonia now. and if they get killed off, then the ammonia spikes and I have to build for a new colony of higher pH nitrifiers. it would be cycling all over again.
I agree I will take the fish out to a bin with a sponge filter and tank water and drip acclimate slow after the 100%. change, before sticking them back into the tank.

It makes the most sense overall. I'm dealing with a pretty big problem, and if it's as bad as I think it is, when I do gain ground on it, it's going to cause problems with the water parameters along the way and kill off the low pH bacteria colonies and I'd be starting over on a cycle anyways.

a month to cycle, or a month to change water and whatever might come with that along the way and possibly cycling over again anyways..... probably the month to cycle if it comes to that, I've got sponge filters to kick start off of once I've got water conditions the bacteria can live in. i'd rather get it sorted out quickly and deal with starting a new cycle. than doing what I've been doing. the worst thing about what I've done for the last 5 days is I've done 5 20% water changes and the pH hasn't budged from below 5. and out of the tap it's about 7.8-8.0. I'm not gaining ground at all, and when gaining on it does happen, there's going to be issues with imbalances that I believe will also distress the fish.

Do you know the KH of your tap water? If it is low then water changes is not going to do much

 

The normal kH of my tapwater is around 120 on a test, the tank is at 0/ super low.

 

Did you ever do the dilution version of the nitrate test as I recommended in an earlier post? Your nitrate levels might be many times higher than you think they are. If your nitrate levels are 2000 ppm, it would take quite a few water changes before you ever get a reading on the test strips.

Since your fish are quite used to the water in which they live, doing a very large water change is a very bad idea. The concentration of every mineral in the water will change drastically causing stress on the fish. Just indicating that your tapwater has 120 ppm KH and your tank is around 0 KH is an indication that there will be a pH swing.

It took several years for your tank to get in this condition. There is no simple, fast way of correcting the problem. Do no more than a 50% water change.

 

I tend to agree with Ray. Since the fish are doing well as is, what's the rush? I'd keep doing normal level water changes more often. Maybe slowly ramp them up as you go. Since your source and tank water are so far apart, even these water changes have to be making some amount of a difference.

 

I did a dilution test, 9 tap to 1 part tank and it brings me down to 25 nitrate as far as the test showed. pH back up and kH back up.

however. doing it in baby steps I'm not making headway at all. nothing has changed and Ive done now 6 daily 20% water changes. 90 gallons have been changed and no change at all for Nitrates, pH or kH
pH is still down below 5, kH is still not even testable. dilution test shows the same thing with 90% tap water, it tests fine but it's not testing lower than 25 nitrates either.

At this rate I'll have changed 450 gallons in a months time, and maybe gotten nowhere still as far as I can tell.

And well the rush is, I want it straightened out and I want it done and then to take care of it from then on as I should. I don't want to spend an hour every day doing a water change to get nowhere, I don't want to spend 450-900 gallons of water to get there (or maybe not get there) either.

I do appreciate the responses and the advice, don't get me wrong, I did this to myself by being neglectful, but if 90% tap water makes it right and get it back testing in line, then why didn't putting 90 new gallons into a 72g make it right already or even ding it?

Frustrated at myself and at the situation. the fish are going into a sterilite bin temporarily with a sponge filter, the tank is getting a 90+% water change, as much as I can get out of it in one shot, and the fish are going to get drip acclimated to the tank.

if 90% new water works for the dilution test, it will work for the tank also. It's just logical, however doing it in baby steps I've already changed over 100% of the volume and got nowhere on it maybe diluted it a tiny bit, but nowhere near progress after 6 days and 90 gallons of water.

The fish, they will need to slowly adjust to the new water parameters on a smaller scale without so much water volume involved. I'll drip from the tank, and takeout water from the bin until both test the same. Best I'm gonna be able to do here. I'm not spending a month daily changing water and maybe getting nowhere with it at the end.
I tried it, it's not feasible it's not doing much of anything at all.

 

I do appreciate the responses and the advice, don't get me wrong, I did this to myself by being neglectful, but if 90% tap water makes it right and get it back testing in line, then why didn't putting 90 new gallons into a 72g make it right already or even ding it?

Sorry but this the dilution effect. 6 20% water changes is only a 74% water change. You've only effectively changed 56 or so gallons of water.

There's probably a lot of acidic waste in there that's eating up the KH as you put the water in.

This is why a big water change is needed. Small water changes will not do anything

 

Sorry but this the dilution effect. 6 20% water changes is only a 74% water change. You've only effectively changed 56 or so gallons of water.

There's probably a lot of acidic waste in there that's eating up the KH as you put the water in.

This is why a big water change is needed. Small water changes will not do anything

yeah, that's where my belief lies on it at this point, I'm spinning my wheels not accomplishing much and wasting water. Where, with a big change, near all the water in the one shot, and then drip acclimating the fish to the better conditions which would get me there a lot sooner, save time and water and work overall. just re-acclimating the fish out of the tank and reintroducing them after. it seems like the more sensible option than trying to do it with them in the tank also.

Im not gonna just plop them in there though, I'll wait until their filtered bin of the old tank water test good again from a drip exchange, before moving them back in. it's just seems like the most sensible course of action after trying it the other way for almost a week and seemingly getting nowhere.

 

A pH of 5 is far lower than typically recommended. Even most blackwater tanks operate at a pH of 6 or higher. There are some South American black water species that live in pH this low, but it is quite unusual for most species.

The low pH is confirmation of the high nitrate levels in your tank. When dissolved in water, nitrates form nitric acid which drops the pH. Normally, water changes or use of buffer compounds helps keep the nitric acid under control.

With a KH of 120 ppm, your tap water is probably 7.0 or higher. A pH of 5.0 is 100 times more acidic than a pH of 7.0. If you do a massive water change, the pH will change drastically, perhaps more than the fish can tolerate. You could lose everything in your tank.

If a 20% water change is not showing enough progress, try 30% or even 50%, but you are taking a big risk if you go much higher than that. If your fish die, you have not accomplished anything.

 

Hi All, Just an update on this after all these months and water changes.

I've Still got a pH around 6, but it's come up some from where it was when I started. I've still got 0 KH even after months of water changes with 6dKH water I think I have some little bit of KH from it just not testable really, I've got normal GH levels now, 0-25ppm (1-2dGH) instead of it being huge and it's now in line with my tap water, and since the last water change, I've gone cloudy again and getting diatom and algae and bacterial action which I haven't seen in years. I think I'm close now to recovering it and the pH coming up and the KH finally returning.

My pH has not come up to my tap of the 6.8-7.2 range. it's darkened a bit, but still low. I've been keeping my nitrates around 25-30 with 2x50% water changes each week, If I don't, my stocking is cranking out over 100 nitrates a week.
my Ammonia and Nitrites have been nil this whole time, no concern there.

I think shortly I will hit that tipping point finally and kick over to holding KH and a rising pH, I also just recently made water changing easier so I can do more in less time now and just staying the course. I'm still hoping that KH and pH don't come slamming back and just slowly rise. which I think by the microbial action going on recently, that's what's happening. I think I'm getting a bacterial bloom from a normal pH colony that's blooming and taking over for the low pH colony. Not sure. I'm optimistic.

Hard to believe it's been 7 months doing this. and still not done, I think doing a full water change would have been better and faster to have been done from the start, but I think I would have likely lost fish doing it, I still can't rule out maybe losing fish when it all normalizes, but so far so good. it's been a mission and a half, but I feel like I'm at the horizon now and it's starting to finally kick over.

 

Thanks for the update this is quite interesting. I never would have thought it would take this long to restore the levels to near your tap water. But it did take years to get to where you were. Maybe having a high stocking level contributed to the slow recovery? I can't imagine it would take as long with just a few small fish.

 

Thanks for the update this is quite interesting. I never would have thought it would take this long to restore the levels to near your tap water. But it did take years to get to where you were. Maybe having a high stocking level contributed to the slow recovery? I can't imagine it would take as long with just a few small fish.

yes, My 26 near adult angelfish do not help, but, I don't think it's that much of a hindrance either with the amount of water changes necessary for them. I have no earthly idea where the KH goes with 100% of the water being changed every week (2x50%) , but it just can't be the creation of nitric acid doing it all. Things really started to turn around when I got the GH down to my tap water range of 1-2dGH from the at least 18dGH. that's when I saw microlife coming back again to the water and I lost my crystal clear. I put the water in at 6dKH, it's zeroed 20 minutes later in the tank.

As far as I can figure, I might be missing electrolytes or cations that were depleted, ran a big deficit, on something, and the KH being added with the water changes is getting cancelled out, a redox reaction that's out of balance that just immediately sucks out the carbonates? maybe it's taking longer because it was zero KH, the pH is coming up and the new nitrifying bacteria is using the carbonates instead of CO2 for carbon? (my filer is high O2 and low CO2)... could be this actually, the KH carbon bonding and making CO2 and being pushed out of the water??

I keep reading, I'm sure I'll stumble across what might be going on somewhere if I look long enough.

there's some science that's over my head there somewhere for what I'm experiencing, it's still not in balance and right, but I feel like it's right around the corner now and one day it's going to just be again.

 

yes, My 26 near adult angelfish do not help, but, I don't think it's that much of a hindrance either with the amount of water changes necessary for them. I have no earthly idea where the KH goes with 100% of the water being changed every week (2x50%) , but it just can't be the creation of nitric acid doing it all.

Even if you were doing 50% water changes every day, you still would not be replacing 100% of the water. This is the same as the puzzle about moving a football halfway to the goal line on every play. On the first play, you move the ball 50 yards. Then is progresses 25 yards, 12.5 yards, 6.25 yards, 3.125 yards (9.375 ft), 4.6875 ft, 2.343675 ft , 1.171875 ft (14.0625 inches), 7.03125 inches, 3.3515625 inches. So even after 10 plays, you are still over 3" from the goal line. This progression can continue infinitely. Although you will get to a tiny fraction of a nanometer from the goal, you will never reach it.

In your case, not only can you never reach the goal, but on every play, the high stocking levels in the tank are pushing you back towards the goal you are defending.

 

Water changed today. KH is still not showing up on tests yet, but my pH is definitely coming up. I'm now at 6.4. I was right about the cloudy water I think, that I was getting bacterial bloom.
Gonna take it slow from here, I don't want my pH in the mid 7s like my tap unless I've given the tank time to get the higher pH colony up to speed. Maybe over cautious, ive had 7 months to get here, but better safe than sorry especially with the stocking I have.
I think the KH is there to some extent now, just below my testable level of 40ppm. Maybe like 20ppm or so.

 

Slwoly slowly wins the race.

Would it be worth culturing a batch of high PH bacteria in a bucket by running a sponge filter etc in hi ph water and adding ammonia./ fish waste ?. Then moving the filter over temporarily.

 

Slwoly slowly wins the race.

Would it be worth culturing a batch of high PH bacteria in a bucket by running a sponge filter etc in hi ph water and adding ammonia./ fish waste ?. Then moving the filter over temporarily.

I have an extra sponge filter in one of my other tanks currently, just don't want to push my luck and rush it, I've got a busy schedule and it might get dumb on me while I'm out and I come back to devastation. But if I notice ammonia come up I'll drop it in and hope it jumpstarts. I think if it can transition to low pH, it can transition back to 7.6 at some point again also without the fish dying as long as I don't rush it, just one colony dropping off as the other picks up. The filter was at normal pH a long long time ago and cycled for it before the OTS. I'm hopeful it's more of a dormancy thing, and not a die off.

Thank you. I have a back up plan, just haven't felt I needed it just yet and not confident it would be enough to change the outcome if it did go sideways on me and I'm really interested on how it goes, as it goes. That extra sponge filter is in a cycled tank now for 3 months it will do something but I don't think it's going to really handle the load I have on the tank entirely, I'm optimistic though I won't ever need it and feel like the biofilter will just transition. It's either going to work out, or it's gonna crash fantastically, it's the only options for it really...


These guys produce 100+ nitrates a week on average, I'm guessing about 27-30 ppm ammonia,
Something like 3-4ppm ammonia a day I'd guess. I don't think a sponge filter could handle it. My wet/dry can, as long as the colonies in it transition along with the water, which at this point I feel like it will, at least all indications say it is doing it.

 

A jumbo sponge filter would handle that bio load ,
820 litres/216 gallons per filter ( lol )
XY-2838 Jumbo HI-FLOW Biological Aquarium Sponge Filter 12 Pack
but I was thinking of just starting some low PH bacteria multiplying in a bucket of dirty water so as to transfer some into the tank .

You are probably right in thinking the bacteria will grow or come back from dormant numbers without any need to add anything. I am probably over thinking the situation?

As I write this I am juggling a large group of Bolivian rams plus tetras ,BN pleco etc back into a tank that has had only mum and tiny fry for the last couple of months. Without testing for ammonia everyone looks and seems to be ok . I choose to do an extra 60 litre water change instead of testing the water.