the filter is the kind that hang on the outside. I also have an
undergravel filter with power heads. I have a lg. fresh water tank, so
have a canaster filter on hand that I pop on there occasionally when
theres trouble, cloudiness, etc. but I don't leave it on all the time.
I figure if my salt water tanks ever has a problem I can clean it and
pop it on it for a while too. deb