Recently bought a 40 breeder off another member. Has an overflow box with a 1 1/2 inch bulkhead and 1 1/2 plumbing for the drain. He wasn't sure how many gph it's good for, also came with a mag5 for the return. The pump seems very weak and I'd like to turn more water over if possible. Please see pictures and let me know what you think, I know it's probaly hard to tell over pictures but any help is great as I'm trying to set this up soon to replace my current tank that only has a hob filter.
Also the return is 1 inch
What seems to be weak return
Tank
Overflow box
Return plumbing
Also the return is 1 inch
What seems to be weak return
Tank
Overflow box
Return plumbing