Reducing Nitrate Without Water Changes

[drobbyb]

the thing about plants, they would much rather use ammonia as food instead of nitrates. In fact, some plants will go as far as converting nitrate into ammonia. This might explain why there is a myth that you need tons of plants to use up all of the nitrate in a tank. If the plants are getting a steady supply of ammonia, then why spend the extra energy to convert the nitrate.

 

[fluttermoth]

You can keep nitrates low using plants, but you have to have a huge amount of plants and a very, very small amount of fish.
It would make a rather dull tank to look at, I think.

ubless you want a tank full of plants and one fish

This myth just doesn't seem to want to die. You can have a very large number of fish -- the real key is in keeping the plants healthy and growing. To keep the plants healthy, they need a steady source of nitrogen -- like a great deal of fish!

Please take a look at some of Diana Walstad's work. She has tanks with no filters that are down right over stocked -- 55 gallon tanks with 80 guppies in it. 55 gallon tanks with 60-70 rainbowfish in them. etc. The plants ARE the filters in these cases. She shows that a lot of the "normal" rules can be broken, if done correctly. For example, she places her tanks so that they get many hours of sunlight each day -- helps the plants be healthy. Diana has an excellent book Ecology of the Planted Aquarium.

Thanks for the info there, bignose; that's fascinating. Something I'll have to read up on; always nice to learn something new!

 

[Bignose]

You can get away with neglecting old full grown fish as you don't see any signs of ill effect but with young fish they need low nitrate otherwise they end up stunted.

May I ask for some evidence of this statement? I have read a fair number of papers on nitrate's effects on fish, and until the nitrate gets very like (like hundreds of ppm), there is no significant effect. We had a good thread in the scientific section where a bunch of people brought together what we all knew at that time. If there is information out there that I missed, I'd really like to take a look at it. Thanks.

 

[ian]

Plants will use both nitrate and ammonia as a food source, they are very adaptable at doing so. As Bignose says, the ammount of nitrate dosed at lethal levels was around 300ppm (i'm sure it was around that number)and that only affected inverts. My planted tanks are dosed around the 60-80ppm every week, dosed every other day, with nil casualties. I didn't do this lightly as the 'old myth' still was at the back of my mind. The only reason i dose the nitrate is because my light dictates the C02 in the tank which in turn dictates the plants needs. Some planted tanks are dosed around 100-150ppm. Like this one...

http/www.fishforums.net/index.php?/topic/278474-1600-gallon-ei-dosed-discus-tank/page__p__2311030&

^^this tank was done by Tom Barr (a memeber on this forum). He has researched nitrate levels and is the one most of us work by when it comes to dosing tanks.

Saying all that, a water change is needed on my tank and in the tank above as you do get an organic build up from the C02 and left over ferts. This can also be tackled to a point though, by using Purigen in the filter or even Carbon. But thats a different story.

 

[merlinblack]

You can get away with neglecting old full grown fish as you don't see any signs of ill effect but with young fish they need low nitrate otherwise they end up stunted.

May I ask for some evidence of this statement? I have read a fair number of papers on nitrate's effects on fish, and until the nitrate gets very like (like hundreds of ppm), there is no significant effect. We had a good thread in the scientific section where a bunch of people brought together what we all knew at that time. If there is information out there that I missed, I'd really like to take a look at it. Thanks.

All I'm saying is that nitrate stunts fish growth so baby fish will stay babies. Once they're fully grown then stunting isn't an issue so any consequence of high nitrate on the fishes health is not as obvious. I'm sure you know a great deal more than me on the subject, I'm new to the forum and just trying to learn a bit more.

 

[merlinblack]

Plants will use both nitrate and ammonia as a food source, they are very adaptable at doing so. As Bignose says, the ammount of nitrate dosed at lethal levels was around 300ppm (i'm sure it was around that number)and that only affected inverts. My planted tanks are dosed around the 60-80ppm every other day, with nil casualties. I didn't do this lightly as the 'old myth' still was at the back of my mind. The only reason i dose the nitrate is because my light dictates the C02 in the tank which in turn dictates the plants needs. Some planted tanks are dosed around 100-150ppm. Like this one...

http/www.fishforums.net/index.php?/topic/278474-1600-gallon-ei-dosed-discus-tank/page__p__2311030&

^^this tank was done by Tom Barr (a memeber on this forum). He has researched nitrate levels and is the one most of us work by when it comes to dosing tanks.

Saying all that, a water change is needed on my tank and in the tank above as you do get an organic build up from the C02 and left over ferts. This can also be tackled to a point though, by using Purigen in the filter or even Carbon. But thats a different story.

You add 60-80ppm nitrate every other day? that looks crazy to me, what level is the nitrate in the tank? why do you do that, I can't keep my nitrate low enough and have to do water changes to remove it yet my floating plants grow like mental and I keep thinning them down. I'm confused as to why you add nitrate??

 

[ian]

If you have a look in my sig at my journal, you'll see how heavily planted my main tank is. Because i have medium light and am running pressurised C02, my stocking isn't enough to keep the plants healthy, hense why I have to dose more. There's more to a heavily planted tank, than a none planted in the way of equalibrium. Like I said earlier I ha e had no casualties and my fish are growing and healthy. The shrimp are doing fine in my main tank.

 

[Bignose]

All I'm saying is that nitrate stunts fish growth so baby fish will stay babies. Once they're fully grown then stunting isn't an issue so any consequence of high nitrate on the fishes health is not as obvious. I'm sure you know a great deal more than me on the subject, I'm new to the forum and just trying to learn a bit more.

Ok, you can say that, but I'm sorry, I'm not just going to take your word for it. This is NOT personal. This is science. No one simply takes the word of another without evidence. Evidence that is hopefully unbiased, objective, and statistically significant if possible.

Turning it around, if you don't have specific evidence on the issue, perhaps you need to re-evaluate whether this statement is true or not. I think that many people worried about nitrates that were getting up to 50, 80, 100 ppm. I mean, the test kit showed high concentrations in a bright red! Read means bad! But, you start digging up the research on it, and fish can usually be fine up to hundreds of ppm of nitrate.

Let me just be clear. I am NOT saying that you are wrong. I am just saying that I'd like to see more evidence of the statement before I accept it as truth.

I am sorry to say, but there are many myths floating around about stunting, too. The bulging organs is one that I don't see as often, but still crops up from time to time. Also, statements like "baby fish will stay babies" is contrary to the way fish biology works. Fish are among the relatively few animals that actually continuously grow their entire lives. That rate of growth may be slowed based on conditions, but it is never zeroed.

 

[merlinblack]

All I'm saying is that nitrate stunts fish growth so baby fish will stay babies. Once they're fully grown then stunting isn't an issue so any consequence of high nitrate on the fishes health is not as obvious. I'm sure you know a great deal more than me on the subject, I'm new to the forum and just trying to learn a bit more.

Ok, you can say that, but I'm sorry, I'm not just going to take your word for it. This is NOT personal. This is science. No one simply takes the word of another without evidence. Evidence that is hopefully unbiased, objective, and statistically significant if possible.

Turning it around, if you don't have specific evidence on the issue, perhaps you need to re-evaluate whether this statement is true or not. I think that many people worried about nitrates that were getting up to 50, 80, 100 ppm. I mean, the test kit showed high concentrations in a bright red! Read means bad! But, you start digging up the research on it, and fish can usually be fine up to hundreds of ppm of nitrate.

Let me just be clear. I am NOT saying that you are wrong. I am just saying that I'd like to see more evidence of the statement before I accept it as truth.

I am sorry to say, but there are many myths floating around about stunting, too. The bulging organs is one that I don't see as often, but still crops up from time to time. Also, statements like "baby fish will stay babies" is contrary to the way fish biology works. Fish are among the relatively few animals that actually continuously grow their entire lives. That rate of growth may be slowed based on conditions, but it is never zeroed.

I don't have scientific evidence, I'm just going off what I've read either in books, on nitrate test kits and what other fish keepers have told me. I am concerned as I have a number of fish which appear to be stunted, certainly aren't growing at any noticeable rate and am trying to provide conditions which will give them healthy growth and a long life. I also want to have good healthy plant growth as that to me is pretty much as important as having healthy fish and I suspect if the plants are healthy the fish will be too. Do you have any evidence of what actually causes stunting?

 

[ian]

thats because the research either doesn't exist or is really poor research, i have searched for a while for some decent evidence and the best i can find is 'The dynamics of growth, the effects of changing area and nitrate uptake by watercress', that is the closest thing i can find searching a uni portol. Bignose may find something a bit closer. The only this that has beed proven is small tanks stunting growth. As per the link i gave you earlier, those discus grew and remain happy in the tank. The plants will let you know if the water is lacking anything, ie Algae, leaf browing ect ect.

 

[merlinblack]

thats because the research either doesn't exist or is really poor research, i have searched for a while for some decent evidence and the best i can find is 'The dynamics of growth, the effects of changing area and nitrate uptake by watercress', that is the closest thing i can find searching a uni portol. Bignose may find something a bit closer. The only this that has beed proven is small tanks stunting growth. As per the link i gave you earlier, those discus grew and remain happy in the tank. The plants will let you know if the water is lacking anything, ie Algae, leaf browing ect ect.

I've got some evidence, read what Steve has attached:
http/www.reptileforums.co.uk/forums/fish-keeping/600790-low-maintenance-fish-keeping-26.html#post7250991

 

[ian]

I was talking about the study into stunting and there not being good evidence...

I don't like linking forums as it's against the rules of the forum, but as it's for the reason to aid this discussion, here goes.

http/www.barrreport.com/showthread.php/3267-NO3-NH4-toxicity-test-on-plants-and-critters?highlight=nitrate+toxicity

that research was done over a number of years and discounts what you have given the link to. I am impressed we are being talked about on another forum
See what they say when you post this. I will just correct myself though, when i said i dose that every other day, i dose it weekly at that amount but dose it every other day. Sorry if it caused any problems.

 

[Bignose]

I've got some evidence, read what Steve has attached:
http/www.reptileforums.co.uk/forums/fish-keeping/600790-low-maintenance-fish-keeping-26.html#post7250991

merlin, this is good. Next time please just link directly to the paper, instead of linking to a different forum, please. I will read this paper when I get a chance. Thanks.

 

[ian]

i will also add this thread to the mix as this has some good discussion regarding the matter.

http/www.fishforums.net/index.php?/topic/336512-do-you-struggle-with-tapwater-nitrates/

 

[merlinblack]

I've got some evidence, read what Steve has attached:
http/www.reptileforums.co.uk/forums/fish-keeping/600790-low-maintenance-fish-keeping-26.html#post7250991

merlin, this is good. Next time please just link directly to the paper, instead of linking to a different forum, please. I will read this paper when I get a chance. Thanks.

I tried to link directly but it said it was too large.