Hi fishy lovers! Got a tank end of june, second hand, absolute bargain off eBay. Will try to upload a picture for you to see. It is 4 ft with cabinet, Eheim pro external filter, power head plus other accessories. £26! We got it ready and left it for a week. Checked the nitrate/nitrite. All ok and added 4 tester mollies. All ok with fish but levels are up. Is this normal? Should I do a water change to help levels or is that going to disturb the natural goings on in a new tank. I have very mixed views about this. Any advice will be loved!