does this sound strange i do my water changes on or two times a week after im done i use tap water and i fill a 5 gallon bucket and i have sand rock filter and airator and a light and let that sit till my next change and the levels come out almost perfect is this a good habbit and secondly i have a biowheel filter thing should i change the wheel and the filter and if so how often the lfs told me to let it get as dirty as possible does this sound right