I am going to be setting up a new tank because I will be moving soon. I am attempting to set up a 20 gallon long while I break down my 65g. I am thinking about purchasing a Bak Pak, but I don't know which one to purchase. I will have live rock and an Emperor filter running. If I get the BP IIR, can I place a heater in the unit or can I only do it on the BP II? The heater does not have to necessarily go in the BP, but it would be nice to have it out of sight.