Hi folks,
I am new to your message board and I have a question. Not really a problem but a question. I have started a new 10gal aquarium with 10 rosey red minnows. I put a biowheel filter on, and have been monitoring the proccess with my test kits. So far I have progressed to the point where I have 0ppm ammonia, 2.0 ppm nitrite and 0.5 nitrate. So the biofilter is just starting to produce nitrate (everything on course). The question is when I setup the aquarium, I tested my tap water with the test kits and the nitrate was 30ppm before I put it in the aquarium. How can it be less now then when I started? I understand it's not unusal to have nitrate in my well water but how can there be less than when I started?
Thanks for any help.
HotDog

Congrats on your new tank and rosy reds. They're great fish. It sounds like your nitrogen cycle is progressing.

Yes, it is fairly common to have nitrate contamination in water, especially if there are farm fields nearby. Once that water is put into the aquarium, the nitrate may take a number of courses.

Some of it may naturally undergo denitrification where the nitrate turns into nitrogen gas which then leaves the water.

Some nitrate may be absorbed by carbon if you have activated carbon in your filter. That would be the main way you'd reduce it quickly with a new filter insert.

Also, some water conditioners contain chelating agents for heavy metals that may have some chemical effect on inorganic ions like nitrate.

Another consideration is the test kit itself. Depending on what exactly it measures, it could have inaccuracies (the results may be wrong).

Finally, nitrate serves as food for algae and live plants. You don't mention if you have live plants but there are probably some algae in the tank (even if you don't see them yet).

Chemistry is in constant flux. Things tend to convert back and forth; few chemicals are stable in an aquatic, living environment.

Good luck Hotdog!