Increase gph in DIY overflow box

[torosax]

Hey guys,

Just wondering if anyone can give me any ideas on how to increase the flow on my overflow. I put in a 500GPH return pump and was worried that it wouldn't be strong enough to keep up with the overflow.. I was wrong.. the water in the drain box is just high enough to slowly flow through the drain pipes.. I wound up putting in a ball valve to slow down the pump, which right now, it's almost completely closed.

Here are some pics and stats about the overflow box..

OFB design..

pics of the actual box..

Return with Ball Valve:

I read that 1" drains should average around 300-350 gph.. There's no way I'm even close to that right now. I could definitely use some more gph from the overflow... Any thoughts would be greatly appreciated!

Thanks,

Betillo

 

[neilanh]

I believe 1" drains can handle up to 600gph.

I think you're misinterpreting what you're seeing (or maybe I'm misinterpreting what you're saying). The water level on the inside box has to rise up high to get the pressure built up to run through the overflow tubes. This is normal and will be the case whether you're pushing 100gph or 10000 gph.

Based on what I see, I suspect your overflow is capable of much more than that 500gph pump can put out. Run that thing wide open and see what it does. I suspect all will be fine.

 

[torosax]

Based on what I see, I suspect your overflow is capable of much more than that 500gph pump can put out. Run that thing wide open and see what it does. I suspect all will be fine.

When I've got it running all the way open, the compartment housing the pump runs way low and then I get a ton of bubbles in the return water going to my tank.. Originally I didn't have a ball valve on the return line.. I only added it after finding out that the pump was pushing out more than what was coming into the sump...

 

[neilanh]

Ahh, now I understand.

So the return section in your sump isn't deep enough to handle it. That's a little different story.

Any way to increase the depth in your sump?

 

[torosax]

Ahh, now I understand.

So the return section in your sump isn't deep enough to handle it. That's a little different story.

Any way to increase the depth in your sump?

Well.. I dunno.. the pump sits 4" high so I set the last compartment to hold 7" of water.. But in the overflow box, the water barely comes up high enough to flow over the opening of the tubes.. that's where I was thinking the problem was..

 

[mr_X]

i think it's those holes you have drilled in the surface skimmer box. they need to be larger/more. then open the pump full blast.

 

[torosax]

i think it's those holes you have drilled in the surface skimmer box. they need to be larger/more. then open the pump full blast.

Ok, I wondered if that was something that I should look at doing.. do you think I should just make them taller or should I try and remove some of the plastic in between them.. or does it matter? haha

 

[cabezon]

Yes, it is the box that is your limiting factor. Most skimmer boxes use slots rather than holes, so that if the water level were to rise the opening would be larger. If the water level on the box is lower than 1/2" below the holes, that's it.

 

[torosax]

Yes, it is the box that is your limiting factor. Most skimmer boxes use slots rather than holes, so that if the water level were to rise the opening would be larger. If the water level on the box is lower than 1/2" below the holes, that's it.

You're talking about the tank water correct? ie. I want the tank water to actually be above the holes/slots?

 

[torosax]

Thanks a lot, everyone! I went through and (although it doesn't necessarily look pretty haha) opened up a lot more slots and now although I still need the ball valve, it's only shut maybe an 1/8th of the way now as opposed to when it was barely an 1/8th open... I'll post pictures tomorrow when my lights are back on..

 

[torosax]

Ok, once again.. Thanks to everyone for the help!! Here's a shot of my skimmer box now...

kinda rough looking but for the most part it does the job.. still have the ball valve closed a little but it's much better than it was..

 

[cabezon]

You're talking about the tank water correct? ie. I want the tank water to actually be above the holes/slots?

That was supposed to be "in the box". The water level inside the skimmer is only a little below inside the tank, outside the box