# How can I reduce the noise in my sump?



## cholile (Oct 28, 2007)

I've asked this question once or twice, but recently discovered that for some reason my 90+ gallon tank was drilled only with a hole that is 1" for the water to flow to the sump. Apparently the standard hole for a tank of this size would be 1 5/8" ?

If so, I imagine this is the main reason I have to endure such an awful gurgling sound as the water flows down from the tank to the sump. Given that this is an established glass tank I cannot really change the size of the hole.

So what can I do?

Previously people mentioned sloped elbows instead of rigid elbows and a flexible drainpipe instead of the rigid pvc I currently have. But will those help if the hole is just 1"?

The thing I don't understand is that a 1 5/8" hole should be able to handle close to 1500 GPH. I have a mag 7 so after the height from the sump to the top of the tank there is no more than 500 GPH being pushed into the tank. So a 1" hole ought to be able to handle that without all this noise shouldn't it?


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## Heyguy74 (Aug 11, 2005)

Try doing a search for a durso pipe. It will stop the gugling sound. They are really easy to make. The sound will happen reagardless of the size of the whole. A 1 inch whole drain at a max of 600 GPH.


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## cholile (Oct 28, 2007)

There is a durso pipe in the overflow box. That's not the issue.

If a 1" has a max of 600 that's probably why there's little I can do about it. If a max of 600 GPH can flow through there the question is whether the max can flow through quietly. I have around 500 GPH flowing right now (hardly a lot for a 90G tank with a sump which is why I cannot believe this tank only has a 1" drain hole).


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## Narwhal72 (Sep 26, 2006)

Hello again cholile.
I am not sure who gave you the information on hole sizes but you have been grossly misinformed.
Perfecto, Oceanic, and AGA/Aqueon drill a 1.75" diameter hole for the drain lines. Since this accounts for 90% of the glass tanks sold in North America it would be considered the standard.
A 1.75" hole accomodates the Outside Diameter (OD) of a standard 1" bulkhead. Bulkheads, like pvc pipe fittings, are sized based off of the Inside Diameter (ID) of the pipe meant to fit them.
I am not sure where the 1 5/8" number you got came from but if the glass was drilled with that hole it would be too big for a 3/4" bulkhead (1.5" hole) and too small for a 1" bulkhead. And also since bulkheads are sized based on standard pvc sizes (1/2",3/4",1",1.25",1.5",2", etc...) a 1 5/8" bulkhead does not exist.
Also the hole size has very little do with your water flow when it's drilled on the bottom of the tank. The 600 gph maximum is based off of the slots in the overflow box. These are really your limiting factor. Bulkhead hole size is more of a factor when the back of the tank is drilled and there is less vertical head space available to build up water pressure. And flow rate has nothing to do with noise level. It has to do with how much water will drain before the tank overflows.

Having seen a picture of your setup before from a previous post. If you wish to quiet your plumbing remove that 1.5" drain pipe and two 90 degree elbows and replace with a 1" pipe and two street elbows (street elbows have a large radius which makes for a smoother turn of the water). That way the water will flow more smoothly and you won't have as much air in the pipe.

Andy


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## cholile (Oct 28, 2007)

Thanks for your comments Andy. I really am lost at this point. Put aside the 1 5/8" v. 1 3/4" for the moment since the person may just have had their numbers mixed up. The hole is definitely 1" and has a bulkhead that has worked fine (e.g. no leaks at all) for well over a year

I have used a valve to take water from the pump and return it to the sump rather than the tank itself thereby lowering the flow from the tank to the sump. This has definitely reduced (though hardly eliminated) the noise. Why would this reduce the noise level if the size of the hole was not an issue?

Instead of hypothesizing I would just try what you suggest but I really am terrible with these things. That is why I paid a lot to have a LFS professionally install the sump in the first place.

I've had a great relationship with them in general so on the one hand I tend to believe their analysis of why the sump has noise. Their view, basically, is that it's an inherent flaw in the design of the tank. On the other hand, they naturally are hardly interested in coming over here and spending an hour or two fixing the sump for free as it costs them, and demonstrates that they messed up all along and I've had to deal with this noise for no good reason.


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## cholile (Oct 28, 2007)

Substantively, here is the explanation given for the noise. I'm giving it verbatim because for all I know the two of you are on the same page and it is me who is just not understanding what is being said (though my sense is that I am following most of what is being said and you two completely disagree as to the central source for the problem).

I've bolded what looks to me to be the key point he's making. It makes sense to me but sounds like you disagree with it?

_1 5/8" is not the interior diameter of the pipe, it is the hole size required for the 1" interior diameter bulkhead. Using standard bulkhead fittings, the largest standard bulkhead fitting that would fit into a 1" hole has an interior diameter of 1/2". I don't remember the exact dimensions, but I believe the bulkhead fitting that came with your tank narrowed to a maximum inside diameter of 3/4", possibly smaller. For comparison, an inside diameter of 1" (area of .78 inches square) will handle a maximum flow of around 800 gph and a comfortable flow of around 600 gph. With a narrower aperture of 3/4" (area of .44 inches square) will handle a maximum flow of around 450 gph and a comfortable flow of 300 gph.

If all of the plumbing fittings were sized to match the hole size, the system would only handle 300 gph through the overflow or less.

*When water flows through a wide pipe, then narrow, then wide again, it has to speed up to accomodate the flow through the system. As the water speeds up, turbulence is created. In addition, the air moving along with the water is forced through the aperature in such a way that in combination with the turbulence, noise is created. The only reason that your tank is not overflowing at the moment is that we used wider plumbing above and below the narrowest aperture. *

A flexible drain hose will not change the problem of the narrow aperture. Moreover, the accomodations required to fit the system with a flexible drain hose would require a "trap" (like under your sink) along the plumbing run and possibly exacerbate the noise issue.

So again, the noise issue is related to this tank being completely innapropriately constructed and fitted by the manufacturer. _


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## brycerb (Dec 23, 2007)

I have a 90 gallon tank with a 1" ID bulkhead and a duroso standpipe and have almost no noise. In fact it is the quietest tank in the house. You just have to work with the standpipe height and the size of the air hole. It is a slow process. It took me 1/2 of a saturday to get mine right. Send me a pm if you want help.


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## terd ferguson (Jul 31, 2007)

In your sump, how far does the water fall from the end of the drain line until it hits the filter pads? If it's more than an inch or so, this could cause a lot of noise. You can double up on filter pads to decrease this distance and decrease noise.

Also, a lid for your sump will greatly decrease water noise. I don't know if you have one or not or if either of these suggestions will help your situation. But, I thought I'd throw them out there in case you haven't thought of them. And these are two things I did to make my sump a little quieter.

Good luck and let us know how and what you do to lessen the noise. It will help others in the future. :thumb:


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## cholile (Oct 28, 2007)

brycerb. I appreciate the offer and do want help. But if I understand correctly you are saying that you have a tank where the bulkhead's interior diameter is 1". My tank the hole itself is just 1" so the ID of the bulkhead is much smaller! That's what I'm told is the problem. Though if I followed what Andy was saying correctly he disagrees.

If I misunderstood you let me know. I'm definitely a little slow when it comes to these things . And it is very frustrating considering how much money I spent on the set up and how much I've learned since that time that I've still been unable to solve the problem (though if Andy's solution makes sense then I just need to find a friend I trust who knows what he's doing to help since I will not try it myself with all my prized fish in the tank and nowhere else for them to go).

ferguson, that's not the issue but thanks for the suggestion. It's a gurgling noise and is definitely due to something prior to the water leaving the pipe and entering the sump. It goes into a column of water on the left (it is an AGA 3 Sump Model). I don't like the sump much but that's a separate matter altogether.

I do have a lid. And it actually increases the vibration noise of the pump. However, you are right that it decreases the other noises.

Sadly this is not my first thread discussing the noise in my sump (many have tried to help) but hopefully for others there is information in the prior threads that helps. Do a search with my name and AGA and sump. That ought to turn up all the threads I've discussed this issue in, but not too many, if any, other threads.


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## Narwhal72 (Sep 26, 2006)

I am afraid the information you were given is still incorrect. A 1" hole will not accomodate a 1/2" bulkhead. You need a 1.125" hole for that size bulkhead. A 1.625" hole will not accomodate a 1" bulkhead. You need a 1.75" hole.

If your tank is indeed fitted with a 1" hole it was drilled not for a bulkhead but for a male thread to female thread connection sealed with a gasket on both sides. This would accomodate a 3/4" pipe fitting. It's an old way of doing things (before ABS bulkheads were widely available) and prone to leaks if disturbed. Dutch Aquarium Systems and Amiracle used to use that method for their seals. However they both used 1" drain lines.

If your drain is only 3/4" the information about changing diameters is correct. You can flow more water than you could if you ran an entirely 3/4" line but there is going to be noise. And a diameter that small is restrictive. I don't know of any professional that would use that small of a drain line unless it was for a very specific purpose.
Your installers information is probably based more on personal experience than any real data. Nothing wrong with that. When I was an installer I went with what worked best for me. However there are a lot of different factors besides hole size that affect flow. And some such as the vertical head pressure allowed to build up above the drain are more important.

Any way you can post a picture of your drain system again? Maybe with a closer view of the bulkhead? Also is your tank glass or acrylic? If it's acrylic you can just drill the hole larger or grind out the hole larger with a Dremel to accomodate a larger bulkhead.

Andy


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## cholile (Oct 28, 2007)

Tank is glass otherwise I certainly would have someone enlarge the hole. It sounds like the problem is as the installer described. The tank I bought was drilled with too small a hole. Wish there was something I could do.


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## brycerb (Dec 23, 2007)

If the hole size is killing your time with your fish, just get a hang on overflow box and block off the drilled hole.


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## cholile (Oct 28, 2007)

don't want to put any more money into filtration on this tank and I plan to upgrade to a 300G in the near future.


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## brycerb (Dec 23, 2007)

Well i think you will have to write this one off as a learning experiance and upgrade as soon as possible. :thumb:


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