Gurgling Overflows

[tbradsh1]

Doing a test of my 125Gallon tank and sump.  I drilled the tank and installed an internal overflow but they are gurgling VERY loudly.  Not sure how to stop it yet.....any suggestions?
 
I really appreciate your help and insight!
Tony

 

[Chad]

I recommend some type of standpipe such as the Druso Standpipe. You can easily make it yourself and it is effective in quieting the noise.
http/www.dursostandpipes.com/make-your-own-diy
 
My tank has the Megaflow overflow kit in it which works to quiet the overflows and adjust drain height.
http/www.aqueonproducts.com/products/megaflow-accessory-kit-for-overflow-aquariums.htm
 
There are other ways but I have found these two are effective.

 

[tbradsh1]

A standpipe would work if the bottom of the tank was drilled but mine is drilled on the side (see pics).  This does not lend itself to a Durso.  I need to find another alternative that can work for my set up.
 
Thanks!

 

[Chad]

Try taking a pice of standard airline tubing, and threating it into the pipe. It's small enough so that it won't block it or reduce flow but tends to quite things down. For a side drilled tank that should work.
 
You can also do a semi standpipe using an L piece of PVC but it looks like your holes are bit near the top of the overflow box.

 

[DrRob]

OK, can't see what you've got in that overflow itself pipe wise but this is what I'd do.
 
Set the 2 pipes up with 2 levels, one lower than the other. The lower pipe ramped down with a ball valve to allow a small amount of water to trickle into the higher inlet pipe.
 
The main pipe will work at full syphon, which will be near silent as it has no air in it, the higher pipe will work with little enough flow to allow the water to trickle down the edges without creating any bubble trapping and therefore no gurgling. You may need to add a T piece to this pipe to allow enough air ingress from above the water level of the tank.

 

[tbradsh1]

DrRob,
I wish I would have thought of that before I drilled the tank!  Makes perfect sense.  I'm thinking about adding a "T" fitting to allow air in the pipes.  I hope I find a solution or this tank isn't going in the way it is.....extremely loud!

 

[Chad]

Are they siphons or actual drains?

The main pipe will work at full syphon...

 

[tbradsh1]

They are drains.  Straight out of the side of the tank down to the sump.

 

[Chad]

I've found that altering the flow either up or down tends to quiet them. A larger pump to push more through or as mentioned ball valves to slow it down to a silent trickle. Which is the right solution really depends on the tank.
 
Either way I recommend ball valves though. You can still add them by cutting the pipes.

 

[tbradsh1]

That's a good suggestion.  Does it matter where I put the ball valves?

 

[Chad]

Personally when I can I put them up high so that water doesn't sit in the tubes but really it can be anywhere along the drain line you want.
 
It's more important for a bottom drilled tank but it can also be helpful on a side drilled as well if your flow is very high. Drains are odd in that there is really a sweet spot for flow that you need to find with them. The valves help you do do that. I have a valve on each return pump and one on the drain line as well as one on each secondary return line so you can tell I like them.