How would you plumb?

[PmCarbrey]

I can't decide how I want to plumb my newest setup, normally I'd aim for a herbie overflow with a 1" full siphon and a 1.5" drain, but the tank I'm setting up (36×24×18) only has a 1" hole and a 3/4". I will be using a vectra m1 as the return pump.

Would a 3/4" main drain with a 1" emergency be able to handle the flow put out?

 

[hijinks7]

3/4 is around 1400 gph so if that's your target flow rate through your sump then you are ok. That's a straight run with no turns or anything just straight down.

Its a smart idea to make the 3/4s your main and 1 inch your emergency. I'd either drill the tank for returns or just to a U hook over the top if you don't mind that look

 

[PmCarbrey]

That was my thought as well, putting the returns over the back seems to be for the best. I've just never used a main drain so small and looking at it made me a bit paranoid!

 

[hijinks7]

Ya my 120g had 2 overflows with the same 1 and 3/4 layout.. I just removed the boxes and blocked off the bottom holes with plugged bulkheads and drilled on the back for returns and a shadow overflow.. I hate the look of the big bottom to top overflow boxes.

 

[Doclight]

I have the same basic setup. What I did is the 1.5" to the sump.. and did a 1.25" return line. Then at the bulkhead I put in a reducer. You still get some head loss, but not as much... Or so I am told.

 

[Reefrodeo]

I concur with using your 3/4" bulkhead as your primary drain, but I recommend 1.25" plumbing above the bulkhead. Pipe perimeter is usually the the most limiting factor in gravity flow is the ability to get the water into the pipe at low head (like a siphon at the surface). You can increase your capacity by using a larger pipe diameter at the inlet, and reducing at the bulkhead, about 15" below the water's surface. The same goes for your emergency overflow. Install as large a pipe as possible (1.5"?). It is more of a weir than anything else, so the pipe perimeter is what governs. (like a glory hole spillway in a reservoir).