Flushing Overflow Box/Bubbles in Sump

happyfeet

happyfeet

Member
Hey guys, I have a CPR overflow box and I built a stockman stand pipe to quit the crashing sound of water flooding into the empty overflow box.
Since installation I've tried a couple variations all with the same results. (You will have to excuse how ugly the stockman standpipe is, Home Depot doesn't actually carry the correct parts so I had to saw apart parts they had and make my own to make it work)
The overflow box flushes (regardless of how many holes I put in the cap, I started with 1 hole 1/16th size and increased to 4 holes 1/16th size, but it was still flushing so I increased to 3 1/16th and 1 1/8th size hole and the same thing happened. I widened another 1/16th hole to 1/8th and it started to make a gurgling noise. (Right now I have all but one 1/8th hole covered with Teflon tape to stop the gurgling sound.
The another problem is in the sump its violently shooting bubbles, to the point where the plumbing shakes.
If I take off the Stockman standpipe it runs smoothly (Minus the sound of crashing water).

(Overflow is empty)



I'm thinking about adding a ball valve at the red X so more water goes over my sheet and expels air that way it might be quieter.


Any ideas on stopping the flushing and the incredible noise from the bubbles?!
 
posiden

posiden

Active Member
How much flow do you think you are running?
Is that a 1" bulkhead?
What pump are you running?
I think right off the batt.......you are trying to run too much through it.
Oh a valve at the red X, might help but it wont cure the issue. You will only be dissapating bubbles across the screen.
 
posiden

posiden

Active Member
Originally Posted by Happyfeet
http:///forum/post/3151075
The overflow box is rated at 600GPH I think its running about 500GPH
I am pretty sure that is a 1" bulkhead. The most I have ever heard of anyone getting out of a 1" bulkhead was 400GPH. That was a straight down run with no 90s or 45s. Is there any way you can cut down the flow to see if it solves your issues?
 
johnr2604

johnr2604

Member
If I remember correctly a 1 inch bulkhead will flow 600 gph at the surface and increase the more head it has on top. Dont qoute me because its been over a year since I looked it up. Where I see the problem being is the air has no place to escape. A few things you can try. One would be to raise the overflow pipe slightly above the surface of the water in the sump. The second would be to add a durso at the bottom of the pipe before it goes in the sump so air can escape above the surface. Three could be to increase the size of the holes on the standpipe to reduce the flushing. Another one that works sometimes is to run an airline down the top of the standpipe and out of the top.
The reason its flushing is there is not enough of a siphon break. The box fills up creating a siphon. The siphon is faster then the return pump so when it empties the box you get that flushing sound as the siphon breaks. This reduces the amount of flow through the box then the box starts to fill again till it makes another siphon draing and flushing again. The key is to get the water draining out of the back of the box not creating any siphon.
 
posiden

posiden

Active Member
Yes, john2604 is right about the head pressure on top. That is why Durso pipes are usually built out of a larger diamter pipe on top then the bulkhead. But this in an OF box and I just can't see you getting any head pressure above the bulkhead.
The air intake down the top is a good idea. The length of the tube would allow you to "tune" the drain to some degree.
Here is an interesting read.
http://www.wetwebmedia.com/BulkheadFloRateArt.htm
 
happyfeet

happyfeet

Member
You get to view some of my art, and I'm VERY bad at art.
Basically what I did, (and it's worked alright) is I ran the pipe to the bottom of the sump, installed a 90 degree elbow added a couple inches of pipe to get the piping close to the glass wall of the aquarium. Then I added another 90 degree elbow and brought the pipe up to just below the surface of the water. Then I added a 45 degree elbow aimed at an angle toward the glass.
This caused the water to slow down a little bit and when it come out it wasn't splashing because it's hitting the glass and sliding down into the water. The air bubbles I was getting are much more silent and I don't get the burping sound anymore.
This is only a temporary solution my main plan is to increase the piping to 2" or 3" at the horizontal flowing parts to slow the water down and increase flow over my scrubber. This should also work to eliminate the air being forced through the piping. (Hopefully)
 
posiden

posiden

Active Member
Interesting. Thank you for updateing. It would be nice if you also let us know how your idea works out for you.
 
happyfeet

happyfeet

Member
I'll try and remember to update this site when I try it out next week. I generally remember to update my club website, but I always forget to update the others.
 
gill again68

gill again68

Active Member
Yeah, hopefully you can post some results. I am having the same issue but not with a HOB I have a Mega Overflow system and its doing the same thing. I can reduce the issue of, mainly bubbles, crashing water but I have to reduce the outflow of the pump to do so. This is getting better results but not great results. I may try the suggestion of a air relief above the waters surface but for some reason I thought it would only create a fountain effect. I guess there isnt enough pressure for that. HMMMMMMMMMMMMMMMMM. I will check this post for updates as well as update my blog on here with my success and failures. So far I had a down pipe that went straight down and was under the surface some 12 inches. Thinking that back pressure was the problem I eliminated the pipe so that it was only 2 inches below the surface. Still had the same results. So back to the Depot for a couple of elbows to allow the flow to slow some and this has not helped either. I will try the air relief tonight to see if better results can be had.
Good luck and let us know.
 
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