Head Loss Question

[FIIISSSHHH]

I was looking to get an overflow box around 300gph and was wondering whether a mag5 or a mag3 would be better. The return line needs to go up 3ft. I have been using Head Loss , but it only goes down to .75 of an inch return line, and I was looking to run a line straight out of the pump at .5 of an inch. So the question is would a mag5 or mag3 be closer to 300gph on the return line.

Thanks

 

[carey]

Better to go with the higher flow, you can alwasy throttle it back with a ball valve. My return is rated for 1500gph and my overflow at 1200gph.

 

[scottayy]

Yes, go higher than what you need. My return pump is rated 600 gph but my overflow box only 300gph. I have a ball valve to adjust but it still almost pumps at full force (this is because I have a tee and split the return line into two).