Nitrate

[French47]

Is it possible to run a heavily plant tank with fish at zero Nitrate? and / or is it desirable.
Thanks

[Bas Pels]

Personally, I never use any kind of fertiliser for my planted tanks - and most are planted, some even heavily planted (due to the plants themselves)

However, they are sometimes also heavily stocked, and the fish proiduyce what the plants need.

Still, 0 nitrates will hardly be possible. But adding plants to a tank without taking real care of the plants? Easily

[.Plecomania.]

what, 0 nitrates hardly be possible? whenever you run a heavily planted tank such as iwagumi or any dutch style, and you dose correctly you will have 0 nitrate. just don't overstock the fish.

you end up having a very nice planted tank with extremely clean water.

[JamesFish]

It is hard to get to 0. The tap in the UK at least contains well over 10ppm and in my area over 20. So even if I fresh fill a tank its going to be at 20.

Going forward it gets harder.

Example

If I changed 50% and my tanks at 80 it doesn't go to 40 because I am starting with 20 in the tap water so it actually lands around about in the middle of the 2 at about 40-50 not the massive drop you were expecting from such a big water change. Yes plants will help to reduce the levels but not enough past a fully stocked tank.

If you were to start with 0 in the water and add in the minerals you needed to RO it might work. I'm looking for ways to reduce my taps nitrate but nothing cost effective has come up.

Options I have considered
1)Lower the stocking levels and increase the plant - Overall effect will be a reduction but dead or dying plants can lead to nitrate.
2)Mix in a small % of RO water - Has other side effects on PH & things
3)Use 60-100L of RO a week adding in the minerals and buffers I need
4)Use a reactor to remove the nitrate - Expensive and if goes wrong can wipe a tank out.
5)Use a filter media to remove it and replace it periodically - Expensive long term and if you run out a shock for the fish on water change day.
6)Nitrax packs have one I have tried to recharge it will try it out when I get time but a bloody nightmare to recharge with salt water.

Looking at the dutch setup it looks like a heavily planted tank here's a link. From a quick peak looks like you use plant instead of fish for impact and the fish are a nice bonus in small numbers.
http://www.practicalfishkeeping.co.uk/c ... p?sid=4627

The holy grail of every keeper is to keep his / her fish in the best of health with minimal cost / effort. Its a balancing act on each persons time / pocket to what can be done.

[dw1305]

Hi all,

Is it possible to run a heavily plant tank with fish at zero Nitrate? and / or is it desirable.

You won't have 0ppm nitrate, you'll probably have about 5 - 10ppm. It is worth noting that it is pretty difficult to measure low levels of NO3- accurately, even with ion selective electrodes. Having no NO3 isn't desirable, as you need nitrogen if you want some plant growth. As an aside aquascapers like Tom Barr have kept and bred sensitive fish at high NO3 levels, but this is where the NO3- ions have resulted from the dissolution of an added salt (usually the fertiliser KNO3), rather than as the "smoking gun" of the oxidation of NH3 (Via NO2-).

Still, 0 nitrates will hardly be possible. But adding plants to a tank without taking real care of the plants?

Yes, you can maintain very high quality water using plants, you just need to aim for slow sustainable growth. I developed the "Duckweed Index", as a technique for maintaining sustainable plant growth, details here, one of which I think is the OP's earlier thread? <http://www.planetcatfish.com/forum/view ... weed+index> <http://www.planetcatfish.com/forum/view ... weed+index, but basically you use the colour, and growth of a floating plant (I choose a floater as these have access to aerial CO2) as a proxy for tank nutrient levels.

The tap in the UK at least contains well over 10ppm and in my area over 20. So even if I fresh fill a tank its going to be at 20.

This is the big advantage of planted tanks, nitrate levels will tend to fall rather than rise.

Yes plants will help to reduce the levels but not enough past a fully stocked tank.

No honestly plants can remove huge amounts of nutrients, plant microbe/systems (with floating and/or emergent plants) are about an order of magnitude more efficient at biological filtration than microbe alone systems. In a microbe alone system we also have NO3 levels rising, unless we have anaerobic out-gassing from a plenum etc. Plants remove NH3?NH4+, NO2- & NO3-, and are net oxygen producers, it is a win-win situation.

cheers Darrel

[.Plecomania.]

When my tank looked like this, i had 0 nitrates regularly.
that was with CO2 injection though. vals are monsters when they get going. they suck everything out of the water. all those nitrates. i had to dose quite a lot back then.

I agree it is tough to measure low nitrates but my API test kit gave me bright yellow results for nitrate which meant close to 0ppm. good enough for me!

[French47]

Thanks for all your replies, As you can see by the photo my tanks is well planted and I have two 1500 ltr filters running. It was a purely academic question, my mains water comes in at about 15 - 20 ppm Nitrate and my tank is about 10ppm No3 . I wondered if a trickle filter to produce anaerobic conditions might reduce the No3 . But then again is it worth the trouble? My fish are Angels, cory's, a couple of Sailfins, Panaque, an whiptails, so not exactly over stocked.

[David R]

I believe certain terrestrial/semi-aquatic plants like Pothos (Epipremnum aureum) are better at comsuming nitrates than many aquaric species. Plenty of people over on MonsterFishKeepers are running them on heavily stocked tanks with fish like piranha and peacock bass that consume a lot of high protein food and have had very favourable results. They are usually grown with the roots hanging in the tank (or sump) and the vines growing up above the tank. They are also fairly tolerant of low light, and much easier to grow than most aquarium plants.

If you're trying to minimise nitrates then Pothos would be a worth-while addition, along with frequent water changes or a continuous drip system (provided your tap water doesn't have high nitrates!).

[Kif]

Options I have considered
1)Lower the stocking levels and increase the plant - Overall effect will be a reduction but dead or dying plants can lead to nitrate.
2)Mix in a small % of RO water - Has other side effects on PH & things
3)Use 60-100L of RO a week adding in the minerals and buffers I need
4)Use a reactor to remove the nitrate - Expensive and if goes wrong can wipe a tank out.
5)Use a filter media to remove it and replace it periodically - Expensive long term and if you run out a shock for the fish on water change day.
6)Nitrax packs have one I have tried to recharge it will try it out when I get time but a bloody nightmare to recharge with salt water.

You could also look at using collected rain water.

[dw1305]

Hi all,
Your tank looks really good, I don't think you are ever going to have any problems with rising NO3 levels.

I wondered if a trickle filter to produce anaerobic conditions might reduce the No3.

I like trickle filters, but I would keep everything aerobic and throw away the test kits. High level of oxygenation ensure that any NH3 is converted to NO3, and your plants take up NH3/NH4+, NO2- & NO3-. The real advantage of a "wet and dry" trickle filter is that it has a huge gas exchange surface, potentially making it able to deal with water with a high BOD. Some BOD bits here: <http://www.planetcatfish.com/forum/view ... =4&t=35930>.

But then again is it worth the trouble?

It isn't, the balance between aerobic and anaerobic that you need makes the filters difficult to manage. Just keep everything aerobic and use plants to mop up the NO3, it is a robust KISS solution.

i had 0 nitrates regularly. that was with CO2 injection though. vals are monsters when they get going. they suck everything out of the water. all those nitrates. i had to dose quite a lot back then. I agree it is tough to measure low nitrates but my API test kit gave me bright yellow results for nitrate which meant close to 0ppm. good enough for me!

You are almost certainly right that you had low nitrates, because you had a heavily planted tank, but the test result doesn't mean that you had 0ppm NO3. Even if your store the reagents in the fridge (I'm not familiar with the kit, but as you mention yellow, I'll assume they contain the "nitrate reductase" enzyme (rather than cadmium (Cd))?), and give them a good shake, they still aren't going to give you a consistent result at low NO3 levels. The best test kits you can buy are probably the Lamotte ones <http://www.lamotte.com/en/aquarium-fish-farming>, but you still have problems with interference with other anions (particularly chloride Cl-), in fact even ion selective electrodes have this problem.

I believe certain terrestrial/semi-aquatic plants like Pothos (Epipremnum aureum) are better at comsuming nitrates than many aquatic species....

I like these too, this is the "aerial advantage" that Diana Walstad talks about in "Ecology of the Planted Aquarium", Pothos or Monstera etc are very good for this, but floating plants (like Amazon Frogbit Limnobium, water lilies Nymphaea) or emergents (like Cyperus spp.) aren't CO2 limited either. Have a look here for this approach <http://www.tuncalik.com/2010/01/indoor- ... aquariums/>.

You could also look at using collected rain water.

I've done this since the 1970's without any problem. I use another KISS technique to check rain water quality, the "Daphnia bio-assay" <http://www.planetcatfish.com/forum/view ... 1&p=258445>.

cheers Darrel