Return pump

What GHP pump do i need for my 125? I plan on using one inch pipe and I have dual overflows.

 

Depends on a couple of factors. How much water does your skimmer process? This is usually the determining factor in how much water you want moving through your sump at any given time. The overflow will always match the return speed, so if you have a 500gph return your overflow will process 500gph out.

Second is how much flow would you like the returns to provide? If you are using a large number of powerheads for flow the return will be less important. However, if you need that extra flow from the return lines, you will want a higher output pump to increase your gph turn over in the tank.

Also factor in head height for your set up, as 500gph pump @ 1 foot is not the same as a 500gph pump @ 4 feet.

Also 1 inch pipe maxes out somewhere in the 600gph range, so that will be a determining factor for you also.

 

Most people will tell you 3 to 5x the display volume or in your case 375 to 625 GPH. The idea is to keep the velocity down in the sump so your skimmer works better and you do not run the risk of carrying microbubbles back to the display with the return.

You make up the rest of the turnover with powerheads such as Vortecs, Tunzes or Evolutions or maybe a closed loop.

 

Thanx guys I already have a mag 7 wasn't sure it it would be enough. Where is the best headloss calculator? I have an sc150 skimmer don't remember off the top of my head what it skims/ hour

 

For mag drive pumps here you go: