Connecting two fx5's to a single return, what size pipe?

[mikeross]

Hello all,

I have 2 fx5, both will have separate intakes but I want to connect the returns to a single pipe.

What size pipe could I use... would 1 1/4" suffice?

Appreciate all feedaback... thank you.

 

[robham777]

Under pressure a 1.25" pipe can handle 3750 gph according to this chart, so it should be more than adequate. I am not sure about the hose id on the fx filters but I think it is 3/4". An insert y connector will run you about $6 from marinedepot. I would imagine there will be some head loss, but it should be minimal.