Major problems with overflow

ryleary · Jan 24, 2015

So I just filled my tank with water for the first time and my overflow is making all sorts of noises and bubbling. I ordered my overflow box from glass holes, and I had to siphon the water to get it to flow down my drain. Is that normal?

I had a tee with a plug that I had to manually siphon to get the flow going, even though there was plenty of water overflowing the teeth.

There are 4 things that may be causing the issue that I can think of.

1. The check valve I have right after the 90 that comes out of my tank. (grey in picture) it is facing the right way.

2. The straw that sticks out of the 90 coming from the overflow box. I have it just poking through, is that how it's supposed to be?

3. the little cap that goes in the overflow box. Maybe it's not snapped in all the way, could that cause it?

4. The reducer from 1.5" to 1"?

Any ideas would be appreciated, I am at a loss and a stopping point because of this issue.

Fin · Jan 24, 2015

You can take the check valve out all together. Why do you have a check valve on your drain?

erk · Jan 24, 2015

Fin said:
You can take the check valve out all together. Why do you have a check valve on your drain?

+1

You only need a check valve on your return. The drain won't cause water to flow back to the sump when the return pump is shut off, but the return will. I imagine you had a problem because the water pressure on the drain wasn't great enough to force the check valve open. I definitely would remove it. Maybe replace it with a gate valve if you don't have one already.

ryleary · Jan 25, 2015

Yeah I figured that was probably it, I'll remove it and see if that helps tomorrow.

Fin · Jan 25, 2015

You want an unobstructed drain line out of the tank. You really don't even need a gate or ball valve. You just want water to run out of the overflow, straight into your sump. Check valves are also not very dependable on your return line. They may work fine in the beginning, but they will eventually fail, which may cause problems if the power goes off and the valve does not stop the back flow. To be on the safe side, you need to make sure that your sump will handle all of the back flow from your tank when the power goes off and just leave the check valve out of the mix.

ryleary · Jan 25, 2015

Fin said:
You want an unobstructed drain line out of the tank. You really don't even need a gate or ball valve. You just want water to run out of the overflow, straight into your sump. Check valves are also not very dependable on your return line. They may work fine in the beginning, but they will eventually fail, which may cause problems if the power goes off and the valve fails. To be on the safe side, you need to make sure that your sump will handle all of the back flow from your tank when the power goes off and just leave the check valve out of the mix.

Thank you, thinking about it now it seems silly to have a check on the return. I'll re plumb tomorrow, hopefully that solves it.

AZDesertRat · Jan 25, 2015

You need to stick with 1.5" on the overflow if thats what it is. Whn you reduce the line size you create back pressure or headloss. The overflow should be as unrestricted as possible from the standpipe to the sump with as few fittings or changes of direction as you can get away with. 45's are better than 90's and valves are not recommended unless you ave multiple overflows with one as a back up.

If you have an airline in the standpipe cap, play with the insertion distance a little at a time up and down, like 1/16" can make a huge difference in both flow and noise.

ryleary · Jan 25, 2015

AZDesertRat said:
You need to stick with 1.5" on the overflow if thats what it is. Whn you reduce the line size you create back pressure or headloss. The overflow should be as unrestricted as possible from the standpipe to the sump with as few fittings or changes of direction as you can get away with. 45's are better than 90's and valves are not recommended unless you ave multiple overflows with one as a back up.

If you have an airline in the standpipe cap, play with the insertion distance a little at a time up and down, like 1/16" can make a huge difference in both flow and noise.

I got rid of the check valve and had to mess with my ball valves, and I got it pretty quiet. Hopefully it holds steady and I don't have any problems. I really had to dial back the overflow drain and that seemed to do it.

AZDesertRat · Jan 25, 2015

NEVER ever restrict the overflow!!! The return pump will always balance itself out with the overflow with a ball or gate valve on the discharge side of the return pump. The oerflow shoule be 100% unrestricted at all times or you are asking for a flood. You should have one ball valve only on the discharge side of the return pump and nothing else.

ryleary · Jan 25, 2015

AZDesertRat said:
NEVER ever restrict the overflow!!! The return pump will always balance itself out with the overflow with a ball or gate valve on the discharge side of the return pump. The oerflow shoule be 100% unrestricted at all times or you are asking for a flood. You should have one ball valve only on the discharge side of the return pump and nothing else.

If I don't there are crazy bubbles and loud noises, don't know what else I can do

AZDesertRat · Jan 25, 2015

You reduce the flow of the return pump so it matches the flow of the overflow. Restricting the overflow will only cause problems. 100% open at all times on the overflowand throttle the return to match it or you will cause a flood.

Here is a good primer on sumps, the only thing wrong is his suggestion on returning water to the sump via a tee which is counterproductive and harder on the pump. Good engineering practice says to install a ball valve inline with the return to the display to add head and actually reduce the work the return pump must do.
What is a sump? | Melev's Reef

ryleary · Jan 25, 2015

AZDesertRat said:
You reduce the flow of the return pump so it matches the flow of the overflow. Restricting the overflow will only cause problems. 100% open at all times on the overflowand throttle the return to match it or you will cause a flood.

Here is a good primer on sumps, the only thing wrong is his suggestion on returning water to the sump via a tee which is counterproductive and harder on the pump. Good engineering practice says to install a ball valve inline with the return to the display to add head and actually reduce the work the return pump must do.
What is a sump? | Melev's Reef

When I open the ball valve on the drain, and have the pump on full, it gurgle and makes all kinds of noises, don't know what else I can do.

AZDesertRat · Jan 25, 2015

Throttle the return pump with a ball valve on the discharge side of the pump so it matches your overflow, not the other way around.

Then as I suggested earlier, experiment with the insertion on the airline tube in the elbow, as little as 1/16 to 1/32" can make a huge difference and once it hits the sweet spot you will be amazed at how quiet and smooth it is.

Fin · Jan 25, 2015

I agree with the above posts from AZDesertRat. Adjust the flow coming from your pump with a ball valve - and always from the pump's output (you don't want to restrict the input). That is how you slow down the amount of water that leaves the tank from the overflow. You are seeing it backwards. You want no restrictions in your drain, unless you are using a multiple drain setup, like a Herbie style overflow.

ryleary · Jan 25, 2015

Fin said:
I agree with the above posts from AZDesertRat. Adjust the flow coming from your pump with a ball valve - and always from the pump's output (you don't want to restrict the input). That is how you slow down the amount of water that leaves the tank from the overflow. You are seeing it backwards. You want no restrictions in your drain, unless you are using a multiple drain setup, like a Herbie style overflow.

I think it may be the 10ft drop into the basement. The water comes gushing down and creates foamy bubbles in my sump and makes the overflow super noisy even if I restrict the pump with the ball valve.

I will mess with the straw coming out of the 90 and see what I can do. Thanks for the advice and trying to save me from a flood, I appreciate it.

AZDesertRat said:
Throttle the return pump with a ball valve on the discharge side of the pump so it matches your overflow, not the other way around.

Then as I suggested earlier, experiment with the insertion on the airline tube in the elbow, as little as 1/16 to 1/32" can make a huge difference and once it hits the sweet spot you will be amazed at how quiet and smooth it is.

AZDesertRat · Jan 25, 2015

Does the oveflow empty under the water level in the sump of drop into it from above? I always have my overflows under the surface myself which seems to work best.

ryleary · Jan 25, 2015

AZDesertRat said:
Does the oveflow empty under the water level in the sump of drop into it from above? I always have my overflows under the surface myself which seems to work best.

Yes, it's a 4-5 inches under the water in the sump when it comes out. For some reason it bubbles like crazy with all sorts of foam spewing out over the filter sock when I open the drain ball valve all the way.

Zacco · Jan 25, 2015

Probably not enough pressure to fully open that check valve on that drain pipe. A 3/4 inch spears check valve is rated at 150 PSI flow and 75 PSI back pressure. I always use the two drain pipe system. My current build has a main 1 1/2" drain pipe on a spears gate valve and a 1" emergency drain pipe that is unrestricted. Ball vavle on the return. I control my flow rate with the ball valve on the return pipe and trim my 1 1/2" drain with the gate to reduce noise. I doubt that a 1 1/2" drain would ever clog, but you never know. Thats why i always run a unrestricted emergency drain pipie directly to the sump.

AZDesertRat · Jan 25, 2015

Your overflow is not getting a full siphon so you are trapping air on the way down that creates the bubbles and foam in the sump.
The basement sump creates a different issue since you now have a much longer vertical drop.
What size is your display tank, sump and return pump and how is the return plumbed? Sounds more like the return is not large enough to keep up with the siphon on the overflow so you are getting trapped air down to the sump.

Do you have any photos or a description of your standpipe arrangement inside the oveflow box? Is there something on the 90 degree elbow inside the box such as a Stockman standpipe so you suck water with a measured amount of air versus surface skimming with unlimited air?