Overflow sounds like toilet

[Mike]

Okay - got the pump thing sorted out, now I've got some questions regarding the overflow. I've got a Durso standpipe, but it's pretty loud. There's a bunch of hissing noises coming from it, a lot of gurgling, and every so often it sounds just like a toilet, and the water level in the overflow drops very suddenly. I'm pretty sure this has something to do with the airflow in it - there's a 3/16" hole drilled in the side of the cap on top of the pipe, through the cap and the pipe, so I can adjust it. If I reduce the airflow, however, it doesn't seem to help. I think the drain pipe into the sump may be too long as well - it is only about 2" from the bottom of the sump. How long should it be? I imagine if it is not under the water level it would be quite loud, but I don't really know. Any suggestions would be appreciated. :thanks:

Mike

[Mckitrick]

Mike,

You need to increase the airflow in the cap.. Try pulling it right off and you'll see the flushing effect (water rising and dropping) stop.

You probably need another hole or a bigger hole. I drilled a very small hole in the very top of my caps (I have two standpipes) and that worked just great!

HTH's.

[Mike]

Thanks! I drilled a 3/32" hole in the top of the cap, and the flushing effect stopped, but I've still got a lot of burbling..... Is the drain tube too low in the sump?

[Dman]

The burbling can be caused by the exhaust being below the water line in the sump.
Raise the pipe out of the water and see if that helps. If it does, you'll need to find a way to contol the splash and an easy way to do that is to shroud the pipe with a larger pipe.
Ttake a length of 4 inch CPVC, drill a bunch of holes in the bottom for the water to escape. Stand it up in your sump and exhaust the pipe inside of it.
Dman
:spin:

[Mike]

Now that sounds like a good idea! Thanks!

[Dman]

I'm using the same type of setup in my sump for my skimmer return.
Dman
:spin:

[Reef Mike]

What size is your standpipe???

You may be flowing to much water. I had the same problem and when I slightly (10%) throttled my return back the overlow went silent, apart from the water dropping 1-2" in the overflow chamber.

Dman is right.. The toilet flushing is due to the back pressure in the overflow line. Either increase the diameter of the pipe or ensure that it is only about 1" below the surface and not directed at any walls or dividers in the sump, as all this adds backpressure.

Mike

[Ocean Images]

Mike, I used a 3" dia stand pipe in my 180, to cure the gurling sound I placed a plastic strainer over the top of the pipe. It works perfectly, all you have to do is rinse the strainer once a week or so. It was a cheap quick fix :)

[Mike]

Thanks guys! The standpipe is 1.5" Sch. 40 PVC pipe. I'm going to get some 4" hopefully tomorrow and try shortening it and putting a shroud around it. I think that will probably do the trick. Thanks a lot for your advice!