[hvc801]

Hello everyone. New to the forum and the hobby as well. I have a 30 gallon tank with live plants and 10 fish (2 dwarf gourami, 2 giant gouramis, 2 black ruby barbs and 1 tiger.. catfish, and two pleco algae eaters) The tank has been running for about 3 weeks now and i keep constant readings and ever since about two days ago the nitrite level went from none to about 4.0ppm and the nitrate as well has gone up a little. I went to the pet store and had spoken with the gentleman there about it and he did not recommend me doing a 25% partial water change due to my tank needs to develope bacteria, and that the nitrite level will gradually get lower and back down to zero once the tank has completed its enitial cycle. I was just wondering if this information is true. I've been reading some posts on the forums about high nitrite but i havent seen anything about a new up-running tank with fish and all in it. By the way, I did not cycle the tank pre-fish. Any help or information is highly appriciated. Also i was woundering when i should actually start doing the 25% partial water changes? Thanks a lot guys.