Return Plumbing Help

[hondacbr600rr]

Need some advice. I am in the process of connecting my 150 gallon tank to a basement sump. This sump will also be connected to my 310 gallon tank.

The total vertical to the 150 upstairs is about 16’, with 2-3 90 degree fittings, and about 4-6’ of horizontal.

I planned to use an Iwaki MD-100-RLT pump. I believe even at that head it’s going to be bigger than what I needed, so I can T off of this line to supply my UV, and reactors.

The plumbing on the pump is 1”, and my tank has 2- 3/4” return lines. Right now the 2 return lines are connected under the stand for an existing sump. This sump will be removed when I connect the tank to the basement sump. I need to figure out if I should reduce the 1” to 3/4” in the basement by the pump, or run 1” through the floor and reduce to the 3/4” T near the bulkheads of the 150 gallon tank? Not sure if it makes a big difference either way, but figured I should ask.

 

[JGT]

Have a similar setup but 1 1/4” at pump and 1” at returns. Not sure if it matters but my
logic was not to restrict outflow near pump but more on return side. Less back pressure on pump was my thinking and it has worked fine.