loud drain to sump (air bubbles), how to quiet?

[nunofs]

Hi,

I've finally finished plumbing my new 75g (will post pictures of the process another time)! It's been running with fresh water just as a water-tightness test since last night in the garage (didn't want to risk flooding the living room), and everything looks good, no leaks and no problems...

But the drain to the sump is quite loud... not the drain itself, which is pretty much silent since I'm using one of the Durso-like kits that AGA sells (the Megaflow kit); the noise is coming from the sump itself, there seem to be lots of air bubbles coming out of the drain pipe, which I have submerged in the sump, and the bubbling is what's causing the noise.

Any ideas on how to quiet this, or limit/eliminate the air bubbles?

Thanks,
Nuno

 

[nunofs]

Btw, I wrote "no problems", but that isn't quite accurate... there was a harmless incident that I found pretty funny... a friend had just been telling me, after seeing pictures of the plumbing, that it almost looked like rocket science...

In that context (think "NASA shuttle launch"), just as I was turning on the switches to the pumps for the first time, I thought to myself "we have ignition"... and two seconds later, the top of the overflow return pipe (the elbow that returns water to the tank, which was not glued) pops loose due to the sudden water pressure and makes a sudden flight towards the ceiling, folowed by a huge jet of water... and I thought... ok, we have lift-off!

Nuno

 

[Clam Man]

I run my return line under water into a filter bag the bag stops the bubbles and the line under water keeps it quiet.also check the height of the return pipe and make sure its correct

 

[3mrhythm]

feed an air line tube into the pipe into the straight down part .. keep the other end out of the tank .. it'll let teh air escape and quiet it down ....

 

[Armando]

i've seen people using flex PVC to create a "downward spiral", with holes drilled on the upper side of the pipe. not sure how effective this is.

 

[JWeb]

Nuno,

I just went through this exact procedure - trying to make my overflow plumbing silent as I tweak my setup. Here is what I learned:

1. The "tube down the throat of the Durso pipe" is excellent advice. This dramatically reduced the amount of bubbling into the sump. It also had the greatest effect on quieting the overflow - nearly silent now (I didn't find the Durso or Stockman overflows to be very quiet by themselves - but certainly quieter than an open standpipe).
2. Use larger diameter PVC, if possible. This was contrary to much of the advice I found during searches, but it worked for me. I rationalized this by suggesting that the larger diameter pipes slowed the flow of water in terms of velocity to maintain a constant flow rate (Q = VA for the engineers in the crowd).
3. Have the overflow piping enter the sump parallel to the surface, with 1/2 a diameter of the pipe above the surface. In this way, the bubbles have a chance to escape from the pipe before becoming submerged. This was also in conflict with some of the advice around that "backpressure" was needed to quiet the overflows down. It didn't seem to matter what amount of backpressure I had, it was always noisy/bubbly.
4. In addition to entering the sump parallel to the surface, have the pipe pass through a foam filter (not sure what you might call it, but a cylindrical filter sometimes used as a pre-filter on overflow pipes) with a PVC pipe cap at the end (to force the water to exit through the filter). This is much like Clam Man's suggestion of using a filter sock - but the filter sock didn't work as well for me. This contraption works really well.

I now have a virtually silent setup - just a slight trickling noise that can be construed as quite soothing. In fact, I think the MAG pumps (a 3 and a 5) are the loudest part of the setup, if that gives you any indication of what is possible. Unfortunately, there is nothing but water in the tank!!

Hope this helps...

JWeb

 

[JWeb]

Here's a picture of how my plumbing enters the sump... maybe it will help.

JWeb

 

[nunofs]

Thank you all for the suggestions! I had heard of the airline tubing trick, but had never quite pictured it in action... and the other ones were completely new to me, namely the details that JWeb posted about the drain pipe being only half submerged... I will definitely try them to see if I can quiet down the bubbling, and I'll report here on the results.

Nuno

 

[ScottM]

run the drain to the bottom of the sump and put a tee to a riser pipe that is higher than the water level, stuff the top of the tube with polyfill and ca it off.

dead silent

 

[NateHanson]

Scott, cap it off with holes drilled in the cap?

 

[ScottM]

Scott, cap it off with holes drilled in the cap?

yup.

 

[Armando]

i'd be afraid of stuffing the pipe with foam. it could clog quickly and cause an overflow.

how about putting the foam around the pipe and not capping it, like in the euroreef skimmers?

 

[NateHanson]

Armando, the pipe with foam is just a vent, with no water flowing through it. Not like the EuroReef outlet. More like a durso vent.

 

[DEIGNAN14]

We just had this very problem. We put a filter sock on the tube entering the sump!
Worked like a charm!

 

[Armando]

I see. It's a tee. So the air will go up the tee and the water will flow to the side without air/bubbles. Is that right?

 

[ScottM]

bingo. its like a long, upside down durso. significantly cuts down on bubbles and and noise.

the polyfill in the vent is just to quiet any noise in the vent pipe.

 

[Daragon]

Scott

where would you tee it off, do you have a diagram. I'm in the same dilema and need to fix it. By the way Aqua-Medic sent me the new cord.

 

[Daragon]

oh, I get it, upside down durso, duuuuhhhhh

 

[JohnK]

I use the same t method that scott is describing. I don't use foam or cap the vent tube at all and it works well.

j

 

[Daragon]

OK, well I tried this last night with no luck. Where you tee it off, is the tee above or below the water line? I mean the tee itself, not the pipe coming from the tee.