Overflow Problems?

J

jeffs86GT

New member
I recently just set up my Sump/Refuge and I am having problems with my overflow not keeping up with my return pump. I have a "u-tube" type overflow (QuietFlow 600) to be exact. My return pump is a is a Mag 5. The mag 5 is rated to flow 500 gph at zero head I think and I'm pushing up at least 4 feet. My problem is the overflow is not keeping up with the return. I can't figure out why though. It has a 1 inch bulkhead and I used 1 inch spaflex and fittings all the way to the sump. The overflow is supposed to flow 600gph but this obviously isn't the case because the tank keeps wanting to overfill. Anyone have any ideas what could be causing this? Thanks in advance.

Jeff
 
Even though the overflows are rated for 600 gph, they really dont do quite that much. You may need to throttle back your pump. If you can make a return back to your sump after the output of the pump with a ball valve you won't put any back pressure on your pump and cause it to wear out prematurely.
 
The QF does not flow 600 GPH. Not even close. I would think it could keep up with a Mag5 though. If the drain plumbing is free of restrictions, I agree with rooroo to reduce flow, but putting back pressure does not decrease the pumps life. Every piece of plumbing you attach to a pump adds backpressure. You could also swap the front cover and turn it into a Mag3.
 
I used a gate valve to adjust return pump flow.

Also the water level in the tank is directly related to the amount of water the hob overflow will flow. If your overflow is adjusted low then it will run slower.

When my overflow was junk I used extra 1" tubing to make an extra u tube. It really helped my junky overflow.
 
Is your prefilter low enough? I had the cut my U-tube on the prefilter side inorder to get it to siphon quick enough so that it wouldnt overflow the display.

The most that should be pumped out from the return outlet is around 280-300gph. I think it has to do more with your prefilter, it might be set too high. Try lowering it.
 
The plumbing is free of restrictions. And I have raised and lowered the prefilter many times with no changes. The water level just keeps rising.

Would cutting down the height of the tube the water overflows into create more flow? Currently the PVC pipe is pretty high in the overflow chamber and I was thinking that if it were lower maybe more water would overflow. (More force? I have no idea)

I still think I'm missing something because it definately should keep up with a mag 5 at 4 foot of head preassure.

Who would have thought that I would be fighting this. I thoght this would be the easy part. I purposely chose the Mag 5 as being under rated for the amount of flow the overflow "should" have had. Damn overflow!!!!

Jeff
 
I have the same overflow on my tank with a Mag 9.5. (I have it teed off with some going to a fuge, some going to the main tank and the balance going back to the sump.)

How far up does your outside box fill up? Do you have the foam thingie on it? If so, get rid of it. My drain goes from the 1" hose into a 2" pipe which goes to my sump. Do you have any air bubbles in your U-tube? Is there a big whirlpool over the drain tube?
 
Outside Box fills up pretty far. Like 1 inch from top.

Foam thing is in outside box around pvc pipe but pushed down below water line. Will remove though.

No airbubbles in U-tube.

Yes there is a whirlppol over the drain tube.

Jeff
 
If the outside box is filling up that far, then the 1" drain line is the problem. Switch it to 2" as soon as you can out of the box and you'll be golden.
 
But isn't the ability to drain based on the smallest diameter in the path? Won't I be limited no matter what by the 1 inch diameter from the start?
 
no. I know it sounds crazy but adding a 2" pipe after a 1" hole will make a difference. But...... a 1" pipe should flow 1 mag 5 worth of water atleast 2x over.

If the outside box is filling that far something has to be blocking or restricting flow on the drain line. If its easy to do go to 2" and it will help you.

Any pics?
 
I have a one inch fitting and hose for my setup and my mag 7 is full throttle without a problem. I would double check the "U" tube and make sure there is no bubble in the top. I have to shake mine to get the bubble out if I break the siphon. A bubble in there will really make a problem.

Eric
 
<a href=showthread.php?s=&postid=8261887#post8261887 target=_blank>Originally posted</a> by jeffs86GT
But isn't the ability to drain based on the smallest diameter in the path? Won't I be limited no matter what by the 1 inch diameter from the start?
Click to expand...

No, friction is the killer. The longer the 1" run, the more friction, the more friction, the slower the flow. That's why the water's backing up in the outside box.

Your U-tube is 1" and your drain is 1" so they should stay even. Since they're not, that points to a problem after the overflow.
 
If you hear a toilet flushing then it is working properly. The drian hose should have nothing to do with it. It has to do more with the siphoning of water into the outside box of the HOB overflow. Get another U-tube and get that runnning along with the one you have now... see if it will suck up and keep up with the pump.

Something is wrong here and it is user error because any HOB overflow box should be able to handle 300gph at min. without any problems.

Please take some pictures of what you are talking about, it will help us help you.
 
I think you will still have the whirlpool effect, as air has be to moved in order for water to flow. Just like flushing a toilet.

Eric
 
<a href=showthread.php?s=&postid=8262331#post8262331 target=_blank>Originally posted</a> by jeffs86GT
So in a properly functioning overflow I shouldn't have that "whirlpool" effect over the drain pipe?
Click to expand...


Yes you will, but the water should only end up 1/4" or so over the top of the drain tube. If it's higher then that, the drain line is undersized.

There should be no flushing sound as it's a "Quietflo". :D

You're not using the black hose that came with it but 1" spa flex instead? As I recall, the black hose is larger than 1" because it fits over the 1" PVC which is 1-1/8" or 1-1/4" OD.

Trust me - your 1" spa flex is the problem.
 
I really doubt it is...

A 1" drain can drain as much as 400gph at the lease. I've seen many threads where people have pumped way more then what he/she has and never had a problem. ITS NOT THE DRAIN HOSE!

Its something to do with the HOB overflow itself, weather its the U-tube or even the adjustment of the prefilter box. Please post pictures, I have a clue of what it might be because I had a problem with my overflow before but fixed it and it works like a pro. dead silent too, i'll show you how to do that once we can figure out why it is not draining quick enough. :)
 
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