I have 0 nitrates in what was a cycled tank

[I_Smell_Fish]

I have a 2 month old 15 gallon tank and the parameters are: Ammonia .25, Nitrites 0, Nitrates 0, pH 7.5. The ammonia is always .25, and also in 2 other tanks that I don't maintain myself. I believe it's the tap water.

I did have Ammonia .25, Nitrites 0, Nitrates 5-10. I had this for several weeks. Then I suddenly had .25 Nitrites and 10 Nitrates. Now it is as I sated in the first sentence.

I just added Zeo-Carb, which is an AquaClear product. I don't know if that did something. I also added PhosGuard to help rid the tank of diatoms.

My fish inventory is 2 mollies, 2 pygmy cories, 1 bumble bee goby. I know it's none of that is good, but there is a master plan. And the goby got in a bag of fish from my lfs. I didn't see it until was home now I can't catch it to get it back to the lfs.

What is going on with the nitrates? Don't I need nitrates?

 

[eaglesaquarium]

Nitrates are not needed by the fish. It is the product of the cycling process, as ammonia becomes nitrite becomes nitrate.

There can be multiple reasons for the nitrate not coming up... the simplest is a testing error. Which is always possible.

Cause 2 would be if you have a heavily planted tank and the plants are using the nitrogen in the tank faster than the fish are producing it.

Those are the biggest two causes.

 

[StevenF]

I have a 2 month old 15 gallon tank and the parameters are: Ammonia .25, Nitrites 0, Nitrates 0, pH 7.5. The ammonia is always .25, and also in 2 other tanks that I don't maintain myself. I believe it's the tap water.

If you think the ammonia is coming from your tap what are the ammonia, nitrite, and nitrate levels of your tap water? Also how did you cycle your tank? Did you buy ammonia at the store to cycle it?

Also do you have plants i the tank?