High Nitrates Level Please Help

[zigzagabout]

Hi can anyone help please. I have just done a nitrates test in my established tank (set up for many years) I have to admit I haven't done one for a long long time as everything has been fine, no illnesses or fish dying ect. The only reason I did one today was because I am in the middle of setting up a new tank so have been doing all the tests and decided to check out my old tank as I haven't been able to get the nitrates level down on the new tank. Hope this is making sense. Anyway it turns out the level was about 40 in my old tank!!! I panicked and did a large water change and have added some live plants (do plants help reduce nitrate?). Anyway I have also checked the tap water for nitrate and this contains about a level 10. So I am thinking that my fish must be used to it being high, what do you think?
Also another reason that I am worried is that I have baby bronze corys in a breeding net in my old tank, but they seem fine (just over 2 weeks old now), is it possible my fish are used to high nitrate? I didn't think fish would breed if the water quality wasn't good.
Any help people please thank you.

 

[fluttermoth]

40ppm nitrate is nothing at all to worry about. Some people on here have that coming out of their tap!

Plants do help reduce nitrate (they use it for food), but you do need to have quite a lot of fast growing plants to make a difference.

 

[N0body Of The Goat]

I have 40ppm out of the tap, which for most fish is not a worry, its when they reach 300ppm nitrates become toxic for most fish.

Nitrate is the most difficult common liquid test to get an accurate result for that we do as fishkeepers. The active compounds that give the colourmetric results come out of suspension in the test bottles and form a sediment on the bottle's floor. Potentially in overstocked tanks with not enough fast growing plants that are given ample carbon dioxide and fertiliser to go with a good lighting period, a lack of substantial enough water changes to remove the nitrate can lead to "mysterious deaths" (which may well be down to nitrate poisoning, with the fishkeeper's false readings giving false reassurance of a well balanced system).