This is my desired set up.
The overflow box I'm getting is rated at 300gph. So I'm trying to determine what my water pump gph
1) How much head loss will I incur by splitting the return line into two like in the above diagram?
2) Also, if the pump has a 3/4" outlet for tubing, after I split at the T connection, should I use smaller tubing (such as 1/2") so there's less head loss?
3) And, could I use all vinyl tubing for this or should I use some PVC
4) Do you think a 500gph return pump would be suitable?