I bleave in water changes I do 50% a week and graval vak and in my 180g the nitrates have not gone over 10 in the 5 years it has been sett up so if water changes didn't work then my nitrates should be wuch higher

you should check your tapp water it maybe 15 alsoeveryone thinks that they are smarter than the next guy here damn!! All I know is I do a 50% change weekly and my nitrate is 15ppm never moves.. thats all the proof I need and I didn't even have to do any math woohoo!!!!!
you should check your tapp water it maybe 15 also