Noisy overflow

[kiwis]

So I've recently got a Aqua One Mini Reef system (120L), link at the bottom. The system seems to work very well however the overflow drain is ridiculously noisy. Like I can hear falling water right now in another room.

The water flows through into the weir and down into the drain as per this picture (1 is down, 4 is return). It's falling into the sump and I believe this is where the noise is coming from. The sump is filled to the specified level.

Can I please have some advise on how to quieten this system.

http://www.aquaone.com.au/2018-02-20-00-40-42/aquariums-3/minireef/item/3381-53419wh

 

[Tony's Reef]

Picture is not working. But have you tried adjusting the air intake at the top of your drain? If you close it off it should produce a full siphon and if you open it up, it should introduce more air. However, I suspect you are referring to part 3 where it goes into your sump. Is part 3 below the water line? If not, try extending it into the water so you don't get that falling water sound. I'm running the same Durso setup with a custom sump I built with two outlets into the sump. I get a LOT of bubbles and every now and then I get a surge of water going into the sump. I need to enlarge my hole slightly, just too lazy to do it lol.

 

[VG30DE-TT]

I had the same issue with that style overflow. The noise seems to come from the system pulling a siphon and then gulping air. A gate valve just above your sump will let you tune the flow so that you can achieve max flow without gulping for air. Although you'll quickly find your self tweaking the valve twice a day.

 

[Tony's Reef]

The noise seems to come from the system pulling a siphon and then gulping air

That is exactly right and is a sign of not enough air in the hole at the top. And not to say to not do what VG stated about the gate valve, but if you do, make sure you have an emergency overflow in place. I only have the one drain hole in my tank so I just put up with it. But a full siphon overflow would be awesome!

 

[kiwis]

There is a small hole at the top of the drain. To make this bigger I would literally have to drill a bigger hole! Surely this can't be the solution otherwise they would have made this adjustable??

I do get periodic gurgling sound but the vast majority is falling water, no the drain does not go into the sump water. I could look to extend this which would really only contain the noise right? Wouldn't actually stop it. Just make the PVC tube a sound barrier.

I've never used a system like this and the logic obviously is for the water to fall down the drain. Are they always this noisy or is there some art to getting them quiet?

 

[Tony's Reef]

when they make these Durso's they guess at the size of the hole. If I was running a 5000l/h pump and it was silent, if I put on a 10,000l/h pump it would start surging. Best thing to do is to drill it out for a larger than you would ever need gate valve and adjust the air flow into the Durso to almost give you a full siphon but still allow enough air to keep water flowing.

And putting the PVC into the water, even just an inch or so, would stop that water splashing sound. You will still hear it, but not from another room in the house. my tank is right outside the door that is behind me, with the door open, and I can't hear it over my skimmer. Here is a picture of mine. It's dirty, but it has been running for 5 years lol. I clean it when I do a water change, which is needed.

 

[kiwis]

I'm so amazed at the noise for an out of the box complete setup.

Surely there's a way of fixing it.

 

[Tony's Reef]

Drilling the air hole will do the best at making it a little quieter and pairing that with putting your output tube into the water, and you will have a pretty quiet system.

 

[kiwis]

Drilling the air hole will do the best at making it a little quieter and pairing that with putting your output tube into the water, and you will have a pretty quiet system.

Thanks, I've sent an email to Aqua One. I'm reluctant to drill anything as I can't undrill it.

The one in the shop was quiet and yes I realise there would have been more noise being a shop however the shop was empty and I put my head in the sump and didn't hear any running water like I do.

 

[Tony's Reef]

Did they have their outflow pipe in the water? I would be interested in seeing/hearing their setup to see how they did it if it is the exact same setup as you have.

And trust me, I know all about not wanting to drill it, especially if it is a brand new tank. But if you do, go oversized and put a small gave valve for airflow on it and adjust it where you want it.

Also, between your tank and the tank at the store, what is the difference in pump sizes / flow rates? That could make a huge difference.

Can you take a video of how it sounds now and post it up?

 

[Erica-Renee]

Without perm modification and best results and least noise
Post 4 on this thread.. You can do this with one Siphon and one safety
https://www.reef2reef.com/threads/bean-animal-help.221303/


Good Luck ..

 

[Erica-Renee]

OHH ALSO Sometimes you can put a rubber tube inside that drain hole in the top and work it around to find the air pocket and quieten it down some.

My above post is your BEST Solution thou . Many are doing those drains as i posted

 

[Tony's Reef]

If you have the option for a second overflow, what Erica posted is best. Full siphon and ultra quiet. And you can try putting a tube into that hole, although I think lack of airflow is the issue here and putting a tube in there would reduce it further. But it is definitely worth a shot.

 

[Erica-Renee]

oh sorry one more thing.. Reducing your return pump will of course make it quieter. You can do this with a ball valve on the output of your return pump...This will NOT HARM the pump.. but it does reduce your turn over...

 

[kiwis]

So I've filled the sump up with water to 'replicate' if I extended the drain. The water is still very noisy.

However you can now actually see the water coming out of the drain. It's hard to describe however it's coming in waves or surges almost as if every couple of seconds more is being pumped or pushed down on top of the usual flow.

I would have thought it should come down evenly?

I've videoed it on my iPhone, not sure how I can upload it.

 

[Tony's Reef]

Not with a lack of airflow. Since you are not getting the airflow you need, it is going to surge.

 

[kiwis]

Here is a video

 

[tbaity1401]

OHH ALSO Sometimes you can put a rubber tube inside that drain hole in the top and work it around to find the air pocket and quieten it down some.

My above post is your BEST Solution thou . Many are doing those drains as i posted

Have you tried this?

 

[Tony's Reef]

Can you show the top in a video? I have never heard one do that.

 

[tbaity1401]

Could be off base here but to me it sounds like the water level in the overflow is covering the air hole at times creating a full siphon for a second and then the water level is moving back down letting air pass. Disregard the green part in the above picture and just try sticking some airline tubing in the hole.