gurgling in DIY overflow

[str8dum]

So I made the DIY overflow as pictured in the sticky thread but I am getting that gurgling burping noise. I've tried to cap the vent with a cap with small holes like i have on my Durso on another tank. That quieted it down some but you can still hear it gurgling and you can see air bubbles thru the intake line.

Not sure how to fix it. The joints are glued and should be air tight and the overflow intake is at the bottom of the tank so I dont know how its gettin bubbles. I sucked all the air out using the 1 way air valve as shown in the pics as well.

Any ideas?

 

[rallysman]

mine did that for a while, but after a while it stopped. it does that for an hour or so when I change water too.
If all else fails, install a ball valve after the overflow so you can slighly restrict it.

 

[str8dum]

yeah the water is defiantely rising and falling in the vent tube. I pulled it off for a second and you can see it going up and down in the T leading to the filter.

Fix?

 

[str8dum]

Another thing, I am running 1" pipe til the T. From the T to my filter i am running 1 1/4" to match my hose.

I have to close the ball valve to less than 3/4 open to stop the gurgling and at the point my 400 gph pump is draining my sump. 1" pvc should flow close to 600 gph so closing teh ball valve to match the overflows max rate seems wrong because according to that my overflow can only drain <400gph.

With the ball valve wide open i can definately exceed my pump capacity but at the level where the noise goes away (ie: max overflow capacity according to the DIY sticky) its barely draining.

 

[MilitantPotato]

My HOB overflow gurgles like mad too, and I get a trickle noise. I've tried a durso standpipe, stockman, and finally got it to stop by using a ball valve (at least the gurgle.)

Stopping the gurgle is easier than stopping the trickle noise, since I need to restrict the flow even more to stop that.
The problem is, if the pump stops, the overflow doesn't flow as fast once the pump turns on again (I have no idea why this is, maybe a vapor lock,) filling the tank and causing the pump to suck air.

I've wrapped the pvc in insulation used for A/C lines, barely helped, if at all.

I've given up on it honestly, I may try removing all of the right angle pieces and use 45's, but I can't see that doing much.

 

[CHOMPERS]

Another thing, I am running 1" pipe til the T. From the T to my filter i am running 1 1/4" to match my hose.

I have to close the ball valve to less than 3/4 open to stop the gurgling and at the point my 400 gph pump is draining my sump. 1" pvc should flow close to 600 gph so closing teh ball valve to match the overflows max rate seems wrong because according to that my overflow can only drain <400gph.

With the ball valve wide open i can definately exceed my pump capacity but at the level where the noise goes away (ie: max overflow capacity according to the DIY sticky) its barely draining.

Can you post a pic of your overflow and the ball valve. A picture is worth a thousand words. You should not need to close the valve 3/4 to make it stop gurgling. If worse comes to worse, put a valve at the bottom of the 1 1/4" hose to restrict the flow there and keep the one at the overflow wide open.

 

[str8dum]

I put a cap on teh vent with 3 x 1/16th holes in it. It doesnt gurgle but the flow is weak

Here are the pics of the loop side and the intake side. the outside loop is about an inch higher than the inside pipe. It restarts and primes perfectly. But the water level goes up and down in the vent making the gurgling noise as it draws in air.

The only thing i can think of is that my ball valve before the vent isnt in the right spot.

I just know that my 400gph pump can drain my sump with the overflow wide open. Somehting not right.

 

[CHOMPERS]

You are correct. The ball valve goes after the tee. The gurggling is caused by the water traveling down the hose at a faster rate than the overflow can supply. The velocity causes a syphon that the overflow can not supply so air is sucked in through the vent.

The overflow in a sense ends at the output of the tee. Think of the hose and the overflow as two separate units. The ball valve should separate the overflow from the hose. The ball valve's job is to restrict the flow going into the hose, which is actually slowing the hose, not the overflow. The ball valve brings the two to the same operating flow.

The solution can be had for around five bucks. Buy a 1 1/4 threaded nipple and threaded valve. Unscrew your hose barb and install the valve there. Add the hose barb to the remaining end of the valve, shorten the hose and you are back in business. Btw, the old valve in the overflow should always be kept 100% open. You will be amazed at the difference when it is fixed. Keep us updated.

 

[str8dum]

i'm not very amazed. with new ball valve in place i have to close it almost 1/2 way to stop gurgling. flow is way under 400gph with 1" pvc. I can put cap on the vent with 3 x1/16th holes and close the ball valve 1/4 and it matches the pump with no noise, but i know thats not correct.

I dunno. maybe the distance between the 2 loops is too big , not your average tank width as in teh DIY sticky. It works, primes, but not as expected.