Just some thoughts here...would it be straight forward as connecting each drain to the inputs of each canister? The output from each canister would come back as the returns in the overflow.
Another thing is if you don't mind running plumbing over the tank (or you didn't want to drill more), to use 1 or 2 of the existing bulkheads as a trickle or dry stand-by drains. You would use strainers on the primary drains, but in case they ever got blocked you would have a back drain taking water to your canisters.
Another thing is if you don't mind running plumbing over the tank (or you didn't want to drill more), to use 1 or 2 of the existing bulkheads as a trickle or dry stand-by drains. You would use strainers on the primary drains, but in case they ever got blocked you would have a back drain taking water to your canisters.
