Drain into sump - hot tub noise

[ap7x]

Hello,

I have a durso (http://www.deepblueprofessional.com/assets/reef-plumbing-kit-assembly-diagram-2-.pdf for reference) with 1" bulkhead. Flow capacity rated 600 gph as normal.

Plumbing for the drain pipe is about 2.5' from bottom of the tank to the sump, with 2 45 degree elbows. I have also put in a reverse durso. Drain pipe is about 2" under the sump water level.

My return pump is Syncra 3.0 (rated 714 gph). The lowest setting is 227.4 gph (return is vinyl tubing).

Basically, if I have the return pump set at the lowest setting (with head loss, a mere trickle lol), everything is silent (overflow + drain). The drain pipe does not gurgle or make noise.

However, if I increase the return pump even 1 notch, the drain into the sump starts doing a "hot tub" effect of bubbling and becoming noisy; this effect increases as I increase the return pump flow. I can turn it to full capacity and the overflow handles it fine (DT doesn't overflow), but the drain into the sump becomes a super hot tub of bubbling and noise (to the point where water splashes out of my reverse durso).

Been doing a lot of searching but haven't been able to find any clear answers. Appreciate the help!

edit: Also, the overflow water level and DT water level are maybe 2"? of difference, so the water trickles down quietly into overflow at lowest setting, if that matters

 

[RobZilla04]

By design the Durso is a noisy drain style. Ensure the air nipple on the top of the drain pipe is open and clear of obstruction. Also you can try taking the sump end of the drain line and positioning it above the water line in the sump. On occasion this will help with the gurgling noise, although neither will be completely silent.

 

[ap7x]

Thank you for the response. So the almost silent (no gurgling) return drain with Durso is only achieved with very low flow rates from the return (as I am experiencing)? The rest is just trying to reduce the gurgle as much as possible?

What is/are the specific reason(s)/cause(s) where increased flow from the return would cause such a dramatic difference in gurgling (and noise/hot tub effect) in the drain to the sump? It goes from near silent at at the lowest setting to "I can hear it from downstairs" at max setting.

I still think I can make some tweaks that may or may not lower the noise based on my searches, but was hoping I was missing some big piece of the puzzle.

 

[garbled]

They will also be pretty silent if you get them to run at full siphon, but that can be really fiddly. You have to tune them into a siphon, and then a siphon has to just happen to be the drain requirement of your system.

On mine I have some adjustable valves on the air nipple at the top of the durso, so I can tweak the siphon. Sometimes if you do this and play with the valves very slowly, you can tune out some of the noise. (Get it to stop cycling up and down, and hold station)

 

[RobZilla04]

Air build up in the drain line causes the gurgling/draining sound. I have a custom cover on the top of my overflow (egg crate wrapped in an old T-shirt nicely contained) which silences a lot of the excess noise.

 

[Ldballoon4]

your 1” drain could improve with no 45 elbows, eliminating back pressure. Mc master carr sells food grade flexible pvc and similar type tubing. That’s what I use. I ditched the elbows. Also, at the top of the durso there is a hole. You can bore it out a little at a time. Use a 1/4” or 3/4” tip of a paddle bit. Use your handle not a drill to open the hole slightly wider.
This should fix the sound. Also like the other poster said have the drain come nearer to the water line, not below it, to lessen the gurgling sound. Durso do have some sound. 600g max is correct.

 

[diverpat]

I went through the same headache as you last month. I have a Deep Blue 57 gallon with the 1" Durso and the 3/4" return. At 600 gph the sound was unbearable. I had to throttle the pump back to less than 200 gph to make it tolerable. After some research I found it is a common problem.

I converted the drain to a Herbie style and now the tank is completely silent. I used the 3/4" bulkhead as the main drain with ball valve to set the water height. I used the 1" bulkhead as the emergency overflow, still utilizing the Durso. I had to make a return manifold which ran up the back of the tank which tee's into (2) 3/4" lines. I can now push 600 gph through the tank with absolutely no noise.

The re-plumbing was very easy to do with 15 minutes of tank down time after I got the pieces lined up and prepped. After adding a powerhead you can hear a little bit of trickle from the water falling over the overflow weir but nothing bad.

 

[ap7x]

Thank you everyone for your suggestions - got some more clarification / new tweaks to consider.

On a somewhat related note, let's say my turnover is 1.5x - 2x, are there any issues I'm missing with such a low turnover rate other than a) possibly... skimmer might be re-circulating same water too much (it is rated 250ish gph and my return pump gph might be around 100 gph with headloss atm)? and b) possible temp concerns with heater in sump? Observed temp swings seem to range from 76-77.5 so not too bad... DT flow is through tunze and gyres so not worried about that.

Thank you all!

I went through the same headache as you last month. I have a Deep Blue 57 gallon with the 1" Durso and the 3/4" return. At 600 gph the sound was unbearable. I had to throttle the pump back to less than 200 gph to make it tolerable. After some research I found it is a common problem.

I converted the drain to a Herbie style and now the tank is completely silent. I used the 3/4" bulkhead as the main drain with ball valve to set the water height. I used the 1" bulkhead as the emergency overflow, still utilizing the Durso. I had to make a return manifold which ran up the back of the tank which tee's into (2) 3/4" lines. I can now push 600 gph through the tank with absolutely no noise.

The re-plumbing was very easy to do with 15 minutes of tank down time after I got the pieces lined up and prepped. After adding a powerhead you can hear a little bit of trickle from the water falling over the overflow weir but nothing bad.

That is exactly my situation lol - Deep Blue 57g, unbearable sound at 600 gph, throttling the pump back to like 100 gph with headloss makes it pretty silent. Might have to consider the Herbie as well...