Uh oh..I"ve been reading the posts here and wondering if I am I underfiltrated? I have an AquaClear 70 on my 46 gallon tank. I love the filter too. It is rated at 300 gallons per hour and up to a 70 gallon tank. By a '10X' rule, should the 300 gallons/hour be 460 gallons/hour? If so, my buddy has given me his Eheim 2213 canister filter as he is out of the hobby now. It's been sitting in a carton. Run both? Switch over? Stay put? Any opinions? All parameters are good and fish are happy. SH