120g overflow plumbing help

[Flynsqwirl]

I have a tank I'm setting up and it has one 2" and one 3/4" for overflow into the sump. Should I use the 2" and choke it down with a gate valve or use that as the emergency and use the 3/4" on a gate valve? These gate valves are pricy and hard to find in that size. TIA

 

[tbrown]

For a 120 I'd think the 3/4" would be a small drain. My 70 uses a 1.25" drain and 1.25" emergency overflow. It uses a 1" return.

If they're both drain pipes I'd consider the 3/4" with the gate and the 2" as the emergency. If it backs up, I'd want to make sure my tank doesn't overflow.

 

[Flynsqwirl]

For a 120 I'd think the 3/4" would be a small drain. My 70 uses a 1.25" drain and 1.25" emergency overflow. It uses a 1" return.

If they're both drain pipes I'd consider the 3/4" with the gate and the 2" as the emergency. If it backs up, I'd want to make sure my tank doesn't overflow.

That's what I was thinking of doing. 3/4" is pretty small but that's what I got. It was originally set up using two 3/4" external returns into the tank and the 2" as the drain and the other 3/4" going into the internal overflow box that was drilled out on each side with return heads. I plugged them up as I'm worried about check valves and the whole tank draining. I can't imagine how load a 2" drain going straight into the sump was with that setup.

 

[tbrown]

That's what I was thinking of doing. 3/4" is pretty small but that's what I got. It was originally set up using two 3/4" external returns into the tank and the 2" as the drain and the other 3/4" going into the internal overflow box that was drilled out on each side with return heads. I plugged them up as I'm worried about check valves and the whole tank draining. I can't imagine how load a 2" drain going straight into the sump was with that setup.

I have my ball valve closed a little over halfway to keep the noise down.

 

[UncommonSense]

That's what I was thinking of doing. 3/4" is pretty small but that's what I got. It was originally set up using two 3/4" external returns into the tank and the 2" as the drain and the other 3/4" going into the internal overflow box that was drilled out on each side with return heads. I plugged them up as I'm worried about check valves and the whole tank draining. I can't imagine how load a 2" drain going straight into the sump was with that setup.

Is the 3/4” bulkhead PVC? Or ABS? You might be able to sneak a thinner 1” ABS bulkhead into the 3/4” bulkheads drilled glass hole!

 

[Flynsqwirl]

I have my ball valve closed a little over halfway to keep the noise down.

With 3/4" with dual 3/4" returns idk if it would be closed at all

 

[Flynsqwirl]

Is the 3/4” bulkhead PVC? Or ABS? You might be able to sneak a thinner 1” ABS bulkhead into the 3/4” bulkheads drilled glass hole!

Idk, I just ordered a new bulk head from brs and it came in today. Im not sure what it's made out of.

 

[tbrown]

With 3/4" with dual 3/4" returns idk if it would be closed at all

On my 135 I ran 2 1" drain pipes full open on a HOB overflow.

 

[tbrown]

Idk, I just ordered a new bulk head from brs and it came in today. Im not sure what it's made out of.

Grey or black?

 

[UncommonSense]

Idk, I just ordered a new bulk head from brs and it came in today. Im not sure what it's made out of.

Brs only sells ABS these days, so it’s that!

 

[Flynsqwirl]

Grey or black?

Black