I am looking at purchasing the RO Classic 2000 HOB Skimmer to replace my old BH300F HOB Skimmer I have had forever. My question is that I want to place my Finnex HMO 300 - 300 watt heater in the return chamber in the Classic 2000 like I currently do in the BH300F. The heater is 12" long and needs to be completely submerged. Will my heater fit in the last chamber of the Classic 2000?