I have a 46 gallon bowfront and am putting 1 oscar only in there. I have two marineland 350 biowheel filters. filters up to 140 gallons together. is that enough? how often would i have to change water? thanks guys.
That is more then ample filtration. A 350 can handle a 55 gallon community tank by itself, so two of them on a one fish tank, even if it is an oscar, is more then enough. This is of course assuming you have the Panguin 350 B biowheel power filter.