New Tank Plumbing Schematic

[Chin_Lee]

I would recommend the following:
1) one of the overflow gravity feed into sump from main tank.
2) second overflow gravity feed into prop tank from main tank
3) gravity feed prop tank to sump
4) one pump from sump into main tank
5) take closed loop pump out of sump so it doesn't contribute anymore heat to water than necessary
6) lower prop tank maybe another .5 to a foot
7) if you lower your fuge so that the return (green line) is more or less the same height as the main tank return (red line) you can triple split your return pump in your sump - two for tank and one for fuge (assuming your return pump has to capacity and ability) if I did it this way, I would also gravity feed (blue line) into my sump or prop tank

This way your sump will be your lowest point and you don't have to worry too much if one equipment fails and causing a flood.

Prop tank I think is your propagation tank correct?