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I think some of the latest research indicates that you need approximately 500 times the biomass of a single fish in plants to compensate for nitrate wastes it produces.
that equates to a heavy planted tank about 5 feet long just to compensate for the nitrate produced by a single neon tetra.

HUH ???

One single Crypt would be about 500 times the size of a Neon.

How come I and many others have to ADD nitrates to a planted tank ? I've got a very overstocked tank fish wise, all bigger then a Neon. I have to add Nitrates 3 times a week and still struggle to keep NO3 above 10ppm. At the rate I add NO3 I estimate the plants are using from 2-5 ppm of NO3 per day.

I've got a non -co2 tank, never gets water changes. Add Nitrate to that one too !

For the record haven't had a sick fish in over a year.

Healthy growing plants are by far the best most efficient way to keep nitrates low. Also provide security and a more natural environment. They have to be healthy and growing though. Dying plants don't consume Nitrate.

I don't have to cycle tanks either. A tank full of plants from start up simply won't cycle. They get to the ammonia long before the bacteria can. All plants utilise ammonia for nitrogen, we just don't have enough in our tanks to satisfy them. Adding ammonia is, of course, not a good idea so we add Nitrate.

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Some days you're the pigeon and some days you're the statue.

Remember that age and treachery will always triumph over youth and ability.

I don't think anybody's trying to rub it in. But you did make some very mis-leading comments, some of which are now being contradicted by your last post.

I was talking about quantity

But that's not what you said.

but most people would not wish to add the kind of amounts that a heavily stocked fishtank will provide for the purposes of growing plants hydroponically away from a fishtank.

Nobody suggested doing that.

Which proves that there may be a differential between the actual needs of a plant for nitrates and the effect that people assume plants will have on their aquarium water.

No assumption here, I know the effect of the plants on Nitrate levels. I don't need to test anymore. One look at a particular plant and I know when the Nitrates have bottomed out. I can tell the level far more accurately then the test kits ever could.
How much nitrates plants remove depends on a number of factors - light intensity, how much Co2, plant density and phosphate levels. But they all remove Nitrates, the quantity varies. Because yours may not remove so much (if you trust your test kit, which I never would anyway) doesn't mean you need an acre of Hygro to remove the nitrate produced by one neon.
If it's lightly planted, non Co2 injected and heavily stocked you may not need to add N03.

There is plenty of evidence that shows that high nitrate can slow plant growth in the extremes

Without a doubt high nitrates would have a toxic effect on plants. But the amount is ridiculously high, far higher then your kit is capable of registering. Again we are not talking about those kind of quantities here.
You can test this very easily at home.

and while your fish may not be dead , the growth of your plants may be compromised by high nitrates levels.

The fish will be dead long before you see an effect on any but the most sensitive of plant species. If you try it you may be surprised that you won't see algae either.

I was pointing out the folly of assuming that any but the most heavily planted tanks will remove or use all the nitrates produced from a shoal of fish in conjunction with biological filtration in an aquarium,

Agreed the tank does have to heavily planted, but to be successful at growing plants it helps to be heavily planted. A tank with lots of healthy growing plants is to my mind quite simply the best thing you can do for your fish, bar none. Better then any amount of water changes. I haven't had a sick fish in a year and a half. If Co2 is added the tank can be planted much less densely with the same effect. There are plenty on this board with tanks that are moderately planted that give you their experiences (none of them good experiences) of the consequences of assuming they had enough nitrates or the plants weren't consuming the amount of nitrates they thought. Guarantee every one of them is adding Nitrates now. Most have probably thrown their test kits out the window.

I was trying to point out that most people throw in a few pieces of elodea and assume that will do the job and it wont.

Correct it won't. But I'd rather tell them what would do it then scare them with Nitrate horror stories.

Besides, does anyone here really never do water changes?

Well never say never ! I do have a tank that only gets water changes about every 6 months. Keeping the filter clean helps keep the mulm in check. A good bacterial colony breaks it down pretty quick. Granted it's a bit muckier then other tanks, but not so much to be a complete eyesore, it's trade off. Still looks better then an algae infested tank.

If you do do water changes how can you attribute nitrate control purely to the plants?

Water changes in the kind of planted tanks most are running nowadays aren't done to reduce Nitrate per se. We deliberately dose to excess all nutrients, to ensure constant availability for the plants. The water change is a safety valve, to ensure that excess we put in is not building up. Then we immediately start dosing to excess again after the water change ! It's not a necessity by any means. It's for convenience more then anything, it renders test kits unnecessary, it's a very simple rhythmic routine that's makes it much much easier for people, especially beginners. You can micro manage the nutrients dosing if you are into testing and forgo the water changes. Even then we tend to just suck out water, don't go near the gravel much. Never heard of anyone's fish getting zapped by ammonia pockets. Ammonia doesn't hang around much in a planted tank. That's why they are practically impossible to cycle if planted well from the start.
It's accepted practice now for most aquatic plant hobbyists not to do water changes more then every few months on non Co2 tanks. Has worked well for a great many people for a number of years.

And fyi, I buy fertilizers that are nitrate free, because frankly I need the minerals and trace elements for the plants far more than I need nitrates. Magnesium being something my plants really seem to need occasionally.

Well all plants need those things and they need the Nitrates just as much. All that varies is the quantity and how we get them in there. Some are readily available in fish food/ poo and tap water some are not. Potassium can often be short. Calcium if your GH is low. Low phosphates = lower nitrate uptake. See how it's all linked. This is why we dose to slight excess, to ensure everything is in plentiful supply. There's a huge range to play with in the upper levels before you see toxic side effects or algae.
I always find it strange that people can readily accept the fact that they need to add micro nutrients found in liquid ferts which plants need in tiny quantities on a weekly basis, yet when it come to adding macro nutrients , which the plants absolutely must have in far larger quantities, like Nitrate and Phosphate , they can't get their heads around it. In the same way that people cling to the myth that an organism like algae, which can happily live in nutrient levels measured in the parts per billion somehow need Nitrate of over 40ppm before they can grow !?

Last edited by bensaf at 21-Sep-2005 03:18

Last edited by bensaf at 21-Sep-2005 03:20

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Some days you're the pigeon and some days you're the statue.

Remember that age and treachery will always triumph over youth and ability.

Ok, ok lets not rub it in people, I was talking about quantity, obviously there is nitrate in fertilisers but most people would not wish to add the kind of amounts that a heavily stocked fishtank will provide for the purposes of growing plants hydroponically away from a fishtank. Which proves that there may be a differential between the actual needs of a plant for nitrates and the effect that people assume plants will have on their aquarium water. There is plenty of evidence that shows that high nitrate can slow plant growth in the extremes especially if there is insufficient co2 or oxygen. As to the lethal levels of nitrate on the fish, frankly it depends on the fish, and while your fish may not be dead , the growth of your plants may be compromised by high nitrates levels.I was pointing out the folly of assuming that any but the most heavily planted tanks will remove or use all the nitrates produced from a shoal of fish in conjunction with biological filtration in an aquarium, sure it helps, but I have lots of aquaria stuffed with plants, no overfeeding goes on and the fish arent overstocked and the plants still dont get rid of nitrate enough to be worth depending on , and Im sure many thousands of aquarists will be in exactly the same boat. It depends entirely on stocking levels and I was trying to point out that most people throw in a few pieces of elodea and assume that will do the job and it wont. Besides, does anyone here really never do water changes? There are plenty of other chemicals and by products that would necessitate a water change, not just nitrate. If your tank doesnt have a 100% substrate coverage in plants with total diffusion of roots throughout the substrate detritus will still build up in pockets in the substrate ,and perhaps even then it still will. You are still going to need to remove detritus from the tank. If you do do water changes how can you attribute nitrate control purely to the plants? Unless of course you dont clean them out for years and consider the occasional release of ammonia from dirty substrate to be a minor inconveinience for the fish?

And fyi, I buy fertilisers that are nitrate free, because frankly I need the minerals and trace elements for the plants far more than I need nitrates. Magnesium being something my plants really seem to need occasionally.

Last edited by longhairedgit at 20-Sep-2005 23:34

I am not with Untitled on this one. Or perhaps I was just misunderstood? I have two planted tanks, one is CO2 enriched with high lights and one is a low lights tank and no CO2 but using Flourish Excel. I add nitrates to both tanks. One gets them every other day and the other gets them once a week. I have no algae issues in either tanks.

I think that what I was trying to say that limiting nutrients works in non planted tanks where there's nothing to consume them, that's all.

but people grow lots of aquatic and semi-aquatic plants hydroponically using only fertilisers without resorting to nitrate

Buy all my Nitrate, Phosphate etc from a hydroponics store

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Some days you're the pigeon and some days you're the statue.

Remember that age and treachery will always triumph over youth and ability.

Im with untitled on this one- people blame lack of nitrate for plant deaths but people grow lots of aquatic and semi-aquatic plants hydroponically using only fertilisers without resorting to nitrate or ever having fish. High nitrate if anything can actually slow groth as factors like other chemicals , oxygen and ph have to be in balance with the nitrate.

Hydroponic ferts have NO3 and NH4 in them, Nitrogen is an essential nutrients required for growth.
No matter how you slice it, this will always be true for plants.

I think the biggest issue for this entire disscussion is the test kit itself.

Is it really correct or not?
IME, NO3 test kits are very poor and very inaccurate.

People read their cheapy kits and call 911............

You can call the water dept and ask for the NO3 levels delivered to you. Then see if the test kit come close.

Cheapy kits that measure in 20ppm units, with a cheesy color chart, probably not the best way.................

Lamotte kits run 60-70$, but are accurate.
Making reference solutions to check your kit, not so simple...........but possible if you have KNO3 and something to measure water volume.............

So while everyone has run all over on a goose chase, the test itself may very well be to blame and I would and do always suspect a poor test reading/kit etc every time I deal with an issue on the web with NO3.



As far as high NO3 being bad for plants: you will kill your fish and inverts long before you cause any harm from NO3.........I know because I recently added 100ppm+(probably ~160ppm, my spect only measures to 100ppm) from KNO3 and finally got some shrimp death(I use shrimp as they tend to more sensitive and they are cheap) of 50% after 3 day exposure.

Now adding NO3 instaed of fish waste are two entirely different critters.

Fish food first needs to become NH4, then a good filter might convert some to NO3..........NH4 is opretty btoxic to both plants and fish/shrimsp etc at high levels.

This is why we cannot add more fish to supply enough nitrogen to a CO2 enriched planted tank, but you can with a non CO2 method(growth rate is slow enough to add Nitrogen/NH4 without killing things).

I have 3-4ppm NO3 removal per day FYI in my tanks on average.

Regards,
Tom Barr

www.BarrReport.com

Im with untitled on this one- people blame lack of nitrate for plant deaths but people grow lots of aquatic and semi-aquatic plants hydroponically using only fertilisers without resorting to nitrate or ever having fish. High nitrate if anything can actually slow groth as factors like other chemicals , oxygen and ph have to be in balance with the nitrate.

Wow thank you Untitled and Bensaf. i get it now. Thread bookmarked for further reference!

I am having pH issues at the moment... so I will just go with getting hornwort and annubus since they seem to do well and use the flourish stuff if needed.

thanks again

GFG



_______________________________________
Never be bullied into silence. Never allow yourself to be made a victim. Accept no one's definition of your life; define yourself.
Harvey S. Firestone

Ok, got it now. Yes they need the same things plants need - but in much smaller quantities. For algae they can live on amounts in PPB - parts per billion.

When your test kits reads zero it doesn't actually mean zero. Just levels that are too small to detect. These really low levels are useless to the plant and it stops growing. But it's enough to keep the algae happy. They now have the upper hand.

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Some days you're the pigeon and some days you're the statue.

Remember that age and treachery will always triumph over youth and ability.

Hey GFG!

"What is the algae eating to grow then?"

Bensaf, I think that what GFG means to ask is "if it's not nitrate that causes algae problem, then what is?"

GFG, Algae is a form of a plant and it would use the same nutrients. Limiting nutrients works great to combat algae -- in non-planted tanks. In planted tanks the plants need those nutrients to grow.

So what is the secret to growing plants and not algae? Growing plants! If your plants are happily growing and healthy, they will take care of the algae for you. To do that you have to give the plants all the nutrients they need to grow. These are the macro nutrients (Nitrogen -- nitrate, in our case, Phosphorous -- phosphate, and Potassium) and micro nutrients (iron, boron, etc, etc, etc).

In a non-co2 enriched tank this is fairly easy to do. Nitrates and phosphates are in fish food and the rest should be in your tap water. Flourish excel, which is a source of carbon, will boost your plants even more. Remove anything you might be using to filter out the nitrates and make sure the level is around 5 - 10ppm at all times, and your plants will thank you with nice growth. Then take it from there and observe your plants and their needs.

Last edited by untitled at 29-Aug-2005 01:53

would live plants consume nitrates?

they sure would

EDIT: hey i'm a big fish now

Last edited by Darth Vader at 28-Aug-2005 21:16

I thought if I had no NO3 then I couldn't get Algae?

A myth. No nitrate will get you all sorts of algae. Especially the most ugliest and stinkiest of them all BGA.

..because it has nothing to eat?

Plants like any life form need a source of nutrition. For plants the primary source is Nitrogen. In our tanks the plants will utilise the nitrate to get their nitrogen fix. Without a source of nitrogen growth stops. The plant will then consume it's internal reserves, when that is exhausted bad things happen. Algae can thrive on much much smaller amounts of nitrogen. Once plant growth stalls the algae can survive and thrive on the minute amounts that are useless to plant growth. A grain of sugar is nothing to a large life form for like an elephant (the plant), it's a feast and a half to a small life form like an ant (the algae).

What is the algae eating to grow then?

Sorry don't understand this bit

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Some days you're the pigeon and some days you're the statue.

Remember that age and treachery will always triumph over youth and ability.

Ok, bear with me because I was a big fan of the plastic plant till a year ago and since then I have been killing plants all over the show.

I thought if I had no NO3 then I couldn't get Algae?..because it has nothing to eat? I don't have algae but then I also have a pleco who is eating constantly so maybe I have.

hmmm.

What is the algae eating to grow then?

thanks
GFG

_______________________________________
Never be bullied into silence. Never allow yourself to be made a victim. Accept no one's definition of your life; define yourself.
Harvey S. Firestone

my nitrates are at 0 -> there is my problem?

Yes. Plants are starving. Need to get it up or algae problems will surely follow.

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Some days you're the pigeon and some days you're the statue.

Remember that age and treachery will always triumph over youth and ability.

I wondered about this nitrate business, in my 35 G the plants are looking ropey to say the least and my nitrates are at 0 -> there is my problem?

in 25G they are at 40 by the time a waterchange is needed, so this week I was going to go buy more plants - just simple low light ones to help the Water quality improve. I ll still do my WC because i have been reading about growth hormones and stunting fish....besides i have a nice routine going now with the WC and the feeding....

cheers
GFG

_______________________________________
Never be bullied into silence. Never allow yourself to be made a victim. Accept no one's definition of your life; define yourself.
Harvey S. Firestone

My nitrate is at 40 on the tester thing. How do you lower it?

Um, longhairedgit... you don't need 500 times a fish's mass worth of plants to compensate the bioload...

If a tank is even moderately planted, you should have problems with the nitrate bottoming out (every last bit consumed by plants) and the plants starve! You've got 2 options then - Overstock, or dose nitrates

I've personally had to deal with nitrates bottoming out in 4 different tanks! If yer lucky, and get the situation under control soon 'nuff (like I did) you won't get BGA! The tank becomes a MESS if ya get BGA! BGA usually shows up when nitrates drop below 10ppm...so most people try to keep their planted tanks' nitrate levels 'round 15-20ppm (atleast that's what I've read, and that's what I've done...it's worked for me)

Anyway, back to the topic of high nitrates! 40ppm ain't bad...could stand to be a bit lower, but it ain't too bad. Waterchanges should do the trick just fine. Don't bother with nitrate absorbers (I've never actually seen any anyway ), or anything like that...just do waterchanges

hey i tried the plants did,nt work might of worked if my cichlids would stop eating them i,ve only got three types yellow labs blue morphs and zebra,s and they all thought the plants were a buffet mine never get over.20 ppm so i,ll just stick to water changes:#(:#(

There are loads of methods to reduce nitrate, but simply regular water changes in small amounts and not overfeeding the fish is the best solution by miles, i have tried various resin bags and stuff but compared to the effect they give the cost is ridiculous. And products like tetrabalance as far as i can tell make startlingly little difference. In areas where plant roots do not grow a gravel cleaner is a damn good move, and ocassionally i have found with tougher plants that its a good idea to uproot them and rinse the roots off, and in particular to check the main stem of larger plants for detritus a quick rinse in room temperature water will do hardier plants little harm.

A lot of people think that having a heavily planted tank means that areas of detritus dont build up and that the plants will handle vast volumes of nitrate, but this is largely a load of bull. I think some of the latest research indicates that you need approximately 500 times the biomass of a single fish in plants to compensate for nitrate wastes it produces.
that equates to a heavy planted tank about 5 feet long just to compensate for the nitrate produced by a single neon tetra.

In addition if the plants are finding nitrate levels too much already, their gaseous exchange and growth can be reduced thus making the problem worse.

A tank as clean as you can manage and regular water changes are the only answer.

Just a tip, i find that floating plants tend to make more impact on nitrate levels than rooted ones, so try some !

Those unfortunate enough to live in areas where tapwater is polluted by farm fertilisers , may have to resort to rainwater , and having to add replasement minerals to compensate. Its amazing how many people never think to test the water straight out of the tap.

TY! i guess its from my love to tell stories LOL.