I like the idea of the 4" pvc pipe as I am getting ready to start cultivating my 75g tank so i can get some mandarins. I do have a question about my tank set up. Especially the bottom tank I call it a sump not sure if that is correct or would it be considered a refugium. (My set up is the tank then water exits the tank down to a small box like tank(sump) with a filter pad the water runs thru, then it trickles down like a stair way into the reservoir below then I have 2 Ecobio stones in front of the water pump that puts the water back into the tank, and a protein skimmer on the outside of the tank) My question is should I remove the filter pad and the bio stones and just add the copeopod, or just do the pvc pipe. If i am correct i will need to turn off the protein skimmer for about 24 hours? Please advise Do I need the filter pad and or the bio stones? I have no water issues as it stands. I have 80lbs of sand on the bottom giving me about inch on the bottom. Please advice.