So my boys and I are making the leap from a bunch of 20 -40 g tanks with HOB filters to a 125 g with a canister filter. We are just in the infant stage of setting up the tank and have only decided on substrate (pool filter sand) and heat. Still researching fish, lighting and decorations in the tank. I am getting confused on how powerful a filter I need. I recently purchased a Penn Plax Cascade 1500 elite that is rated for a 200 g tank. I am concerned however about the flow rate after reading some of the threads on this site. It is 350 gph. Do I need to double up or will this be sufficient? Considering African Cichlids ...but haven't decided.