I can't for the life of me find the answer to this question, when running a closed loop what is the ratio of intake to return? for example does a 1 inch intake bulkhead only supply a 1 inch return or can that one inch intake handle two separate 1 inch returns, etc... is there a ratio or a formula? or do i just match evenly. I currently have 6 3/4 schedule 80 bulkheads in the bottom of my tank and don't know how many should be intakes and how many should be returns, running about 2700 gph. please advise, thanks.