I like the concept ijji of taking from the water surface of the tank to help remove that scum rather than under the surface with a power head, what is the purpose of the canister outside the tank rather than having the flow go dirictly in the refugium?? the canisters you are useing are they something you purchased or make them from items lying around the home?? now the flow from out of the main tank is syphon and gravity, are any flow control valves used?? and I assume that a particular water level has to be maintained in your main tank?? what type of pump do you use to push the water back up in to the main tank??
arpartyman
any type of red or green algae is useful, caulerpa is just a better choice, I have feather caulerpa and I got it off a piece of rock that I bought at a LFS, he tried to pull the plant off the rock, but I told him what ever is attached to the rock should be sold with the rock, so I got the plant which is the only reason I bought the rock...lol now I have a bunch of the stuff which I give clumps of it away occasionally, it does grow fast.