Need some ideas on installing a UV setup. Tank is 75 gallons bare bottom and 30 gallon sump. I want the the UV, pentair 18W, on its own pump (any recommendations?) Also want a flow sensor on it, would you put it between the pump and uv or uv to drain. For the flow sensor should I go 2” or 1”? The unions on the uv at 1 1/2”. Does it matter if it’s mounted horizontally or vertically? And last can I just pump from my return chamber and dump in my fuge?