i am setting up a 10 gallon nano and i plan on custom making my own sump because this tank will be for dwarf seahorses and i dont want them hanging on the heater or getting stuck on the filter. i plan on a 5 gallon for the sump with the filter and the heater in there. my problem is how top heat the water if it is constantly moving in and out of the 5 gallon? i want a 200 gph pump in the tank and in the sump to pump the water throughtout the system. and the return will split 2 ways and go to either side of the tank. does everything sound in order? i also plan on having a metal halide system 175 watts over the tank for some zoanthids and colony polyps and maybe 1 or two acro's. some gorgonians and a couple of halimeda plants. just wanted your opinion on things before i get all started and screw up...lol just kidding. my parameters right now are 0 ammonia , 0 nitrate, 0 nitrite, 8.2 ph, 1.025 SG and the tank is always kept between 76-78 farenheit. i have 10 lbs live rock and a tiny little cleanup crew until i get the real crew with the seahorses.