Nitrates won't go away!

[Sursion]

It was time for the weekly water change. My Nitrates were reading 20ppm, so I did a 25% water change. When I was done, I checked water levels, and my Nitrate was still at 20ppm. Confused, I did a whole other water change, this time doing 40%. I checked levels again, and it's still at 20ppm.

What is going on? Why aren't my nitrate levels going down?

[Lady Hobbs]

Nothing wrong with 20 nitrates and still well in the safe zone but could be your filter media needs a good rinsing.........in dechlorinated water.

[Sursion]

What would be the safest way to do that? Safest for the bacteria, I mean.

[Lab_Rat]

Take a bucket of old tank water and rinse the media in that. You may also need to gravel vac your tank. Have you checked your tap water for nitrates?

[Sursion]

Not yet. I should probably do that once the little vials are dry.

[Lady Hobbs]

They need not be dry but rinsed out is all.

[Wild Turkey]

25% waterchange did reduce the nitrate by 25%, anything else is a virtual impossibility.

However, since test kits accuracy can vary, and especially the nitrate test in particular, I think the change just wasnt noticeable via your testing.

Make sure you shake the heck out of both bottles when you test nitrate.

[Sursion]

Just tested the tap water. It came back yellow (0ppm on the API test kit).

Now that I think about it, I did see a lot of crap come up when I was pouring the new water back in. Would cleaning the gravel really make the nitrate levels improve?

[Lady Hobbs]

Sure does. Harbors lots of nitrates and also a very dirty filter.

[jimw/oscar]

Just tested the tap water. It came back yellow (0ppm on the API test kit).

Now that I think about it, I did see a lot of crap come up when I was pouring the new water back in. Would cleaning the gravel really make the nitrate levels improve?

Yeah then like others have said it's either the substrate or filter media. I have mechanical media in front of my bio-media and find my nitrates do drop after I change floss.