120 g tank start up advice please

[Reef Tank Engineer]

Looks like two bulkhead fittings behind the plastic overflow barrier
The lower one is your drain to sump the upper one u can plumb into drain incase one gets plugged up. Have your return pump line retun water to the otherside of you tank so it flow accross.

[Junmity]

Cool,

thank you.

sorry i had no more pictures as the partition was loose so i removed it.

at 120 g how big of a pump should i use for the sump return to tank?

[Nano]

depends on how high your tank sits above the floor and how much flow you want. I have a pump rated at 1090gph on my 35, but run it at about 1/2 right now until I put in sps. you will probably want a good amount of GPH for a larger tank IMO. but I could be wrong.

[Starry]

you want about 5x display volume going threw your sump. so 600gph after head loss.