Having Trouble With Nitrate Readings

HI everyone! I am getting readings of 0 nitrates in some of my freshwater planted and heated tanks. The tanks have some small tropical fish. I test the water with the API master test kit.

The tanks with 0 nitrate have been fishless cycled with fish flakes and have 0 ammonia and 0 nitrite currently. Some tanks (4, 8 and 10 gallons) have hornwort, crypts, lilaeopsis and elodea. Another (23 gallon) is heavily planted has java fern, willow moss, anubias, vals, lilaeopsis, hairgrass and a large amazon sword.

They all finished cycling around 1 month ago. During cycling we got around .25-.5 ammonia and only very slight readings of nitrite. We got readings of around 5 nitrate at the end of the cycle after the ammonia and nitrite went away. Since then the nitrates have been falling. Now they are 0. We put in Marine Pure squares which was seeded from a cycled tank and have been sitting on the substrate.

When I test the nitrate I bang the test bottle #2 on a table, on my leg and shake it like crazy for around 1 minute.

The test bottles were made late last year and expire in 2021. I have 2 test kits and have tried with both of them and get the same readings. I have some test strips (I know they are inaccurate) so I tried using them and it showed 0 nitrate too. Another tank I have tested has 5-10 nitrates.

I do weekly 25-50% water changes and siphon the gravel.

I am worried 0 nitrates could be bad for the fish and plants. What can I do to get some nitrates? Am I testing the water the wrong way?

Thanks for any help you can give me! Hope I have made myself clear.

 

With your tanks being planted I am sure they are using the nitrates up for food. You may need to add more food for the plants actually. If you aren't already.

A tank with no nitrates isn't bad for the fish at all. It means there is no waste build up. Which is very healthy for them actually.

I honestly would consider adding a few more fish if you could. But I want as many fish as I can get lol

 

With your tanks being planted I am sure they are using the nitrates up for food. You may need to add more food for the plants actually. If you aren't already.

A tank with no nitrates isn't bad for the fish at all. It means there is no waste build up. Which is very healthy for them actually.

I honestly would consider adding a few more fish if you could. But I want as many fish as I can get lol

Thank you AllieSten. I am worried that so low Nitrate won't be able to handle adding extra fish. The Nitrate readings seem to go up and down too, but mostly they are low to almost nothing. For example in one tank I had 20 - 40ppm Nitrate and a couple of days later next to zero. What would happen if I were to remove some plants?

I am reading that several other people on Fishlore seem to have the same problem.

 

You could definitely remove some plants and see if that helps. The goal is to keep nitrates between 5-20 in a non-planted tank. For fish health. For a planted tank it is ideal to have nitrates around 40 or so to feed the plants.

So the low nitrates are good for the fish, not so good for the plants.

 

It's confusing! The plants are doing really well!

 

ashenwelt you have planted tanks right? Could you possibly help? APierce Drummindot aquadude91

I have very limited knowledge with planted tanks. So I am just regurgitating info I have read. These guys deal with plants more often. Hopefully they have some better advice.

 

I'd add more fish if possible, if you can't do that start using aquarium safe fertilizer. Try a smaller water change too maybe.