I have a well established (3 years) 75 gallon FOWLR. Up until now I've had a Penn-Plax Cascade 1000 canister filter, along with about 75 lbs of Live rock and a wave pump. After my water change, canister maintenance today; my canister is leaking bad and I've tried everything to stop it....no luck, so I've had to remove it from operation. While I'm waiting for a replacement, I'm wondering how long my tank will be ok. Somebody said I don't even need the cannister, as my live rock is plenty? Any thoughts are appreciated.