You can connect a hose to a Rio, more like a conventional pump then a power head. Seios' are for in-tank use only, only purpose is to move larger volume of water more randomly.
Even if I get the seio1500, I dont think it will heat up the tank that much. I have 4 MJ1200's in there and my tank hits, max 82-83 during the day with the halides on and stays at a constant 81 during night hours. Plus the seios use less wattage, wouldnt that consitute less heat transfer in comparison to 4 mj1200 @ 24 watts each?
I have 17000 GPH in my 180 and i dont feel thats enough Listen as for as to much never to much flow in our systems we can not get the flow that the ocean has
Nick