(2 x 1 inch) or (1 x 1.5 inch?)

[scuba1102]

Looking at rebuilding my HOB overflow since it's so noisy. Currently it has two 1" standpipes. I want to do a stockman off the side(s) of the HOB. Would it be better/easier/quieter to do a 1" off two sides or a 1.5" off one side? Looking to move about 1200 gph.

thanks

 

[xtrstangx]

The 1.5" would be quieter, IMO. It really depends on how you plumb it. When you have 2 drains in the same overflow, they compete for water and can be noisy.

 

[Stile2]

I vote of 2 pipes, 1 - 1" and 1 - 1 1/2", but they need to be plumbed very specifically.

Drain #1 (1 1/2" pipe): short (at least 2" below water surface) straight pipe with gate valve to adjust flow

Drain #2 (1" pipe): Durso standpipe.

With the flow going, adjust the gate valve so that the straight standpipe is fully submerged (a fully submerged pipe, one that does not ever suck in any air, is absolutely the quietest) then the dusro takes any extra. Durso's are quiet if they have very little flow, if you exceed half to two-thirds capacity they become noisy.

HTH
Keith

 

[Ken668]

I agree with Keith, that is the best way go. I currently have the same setup on my overflow and I get comments all the time about how quiet it is.

Essentially, with the ball valve, you max out the one line, and anything extra will flow down the second. It also acts as an emergency drain in the case the first one gets clogged (snail, algae, etc.) So if you're not pulling any air, then you're not making any noise!

 

[Ratkiller]

Can one of you guys post a picture of what your talking about. I'm looking to set up my new tank with over flows.The noise facter keep seems to be coming up alot.

 

[Ken668]

Here is a quick cut-away of what we are referring to. Right drain is primary, and left drain is secondary or emergency drain. With the ball valve, you raise the water level in the overflow so that the primary does not pull any air. If there is any extra flow that the primary can't handle, it will go in the secondary. Same thing happens if the primary gets clogged, again with snails, algae, etc.

 

[Stile2]

I would really recommend a gate valve vs. a ball valve. The ball valve turns out to be very hard to adjust precisely.

I actually purposefully close my gate valve a bit too much to force some water down the secondary (which in my case is a durso) which feeds my fuge.

Keith

 

[CoolUsername]

The single 1.5" will give you about 15% more flow capacity than two 1" drains. The arriangment suggested by Stile2 (keith) and ken668 would be quieter for sure under the right flow conditions.

However, I wouldn't put more than about 500 GPH max down a 1" drain without any flow restrictions. So in principle two 1" drains aren't going to safely handle 1200GPH IMO. Maybe try 2 1.5" drains using Keith's suggested setup. That will handle your flow.

 

[CoolUsername]

.. and be quiet about it.

 

[Ratkiller]

If you did decided to go with the 2 x 1.5 drains wanting 1200GPH I'm curious about what you are running for a return?