# Question: PVC Overflow



## captevo (Feb 4, 2008)

Hello, I'm interested in making a PVC overflow.
What I have:
- 55 gal tank
- 10 gal tank (for sump)
- QuiteOne 2200 - 4ft head height (about close to 400 gph)

Questions: 
- Which size of PVC pipe should I get?
- Is PVC cement safe to use?

Thanks in advance


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## jwal (Jan 17, 2008)

I built my diy overflow with 1.5" pvc and used pipe cement on the outside (not touching water). The only reason I didn't use PVC cement on the water-touching portion is because I wanted to be able to rotate and remove the pipe as needed. You can do snug-fit inside the aquarium with plumber's tape.

Also, 1" PVC should drain approximately 600 gph. 1 1/4" PVC can drain about 950 gph I think. These numbers might be for conventional standpipes but I think a 1" DIY overflow could handle 400 gph.


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## captevo (Feb 4, 2008)

Thanks, jwal.
I'll get some 1"... I'm also thinking about installing valve for both overflow and return pipe so I can control it better if needed.

I'm thinking about going with this design
http://www.saltwaterfish.com/vb/showthread.php?t=288154

Is this the latest? do we still have noise problem?


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## Hoosier Tank (May 8, 2007)

I found this back when I was building my HOB overflow and have refered to it sevel times. Thanks to whoever the original poster was...


> For a drain overflow (not siphon), the flow for various diameters of pipe is:
> .75" = 325gph
> 1" = 600gph
> 1.25"= 900gph
> ...


So I agree with the 1" pipe should be fine but I see no reason to put a valve on the drain pipes. They will only flow what the pump returns to the tank and if you restrict it to less than what the pump returns, the tank will eventually fill too high and spill over.


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## KaiserSousay (Nov 2, 2008)

http://www.aquariumlife.net/projects/diy-overflow/120.asp
I used this design, least amount of stuff in the tank...
http://www.cichlid-forum.com/articles/diy_skimmerless_overflow.php
Bulldogg`s unit works quite well also...Consider using gate valves for your flow control..a little more $$$$, for alot more control.


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## jwal (Jan 17, 2008)

The design here (http://www.saltwaterfish.com/vb/showthread.php?t=288154) looks like mine


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## captevo (Feb 4, 2008)

Hoosier,
Thanks for flow warning, but I'm paranoid , i think i'll put one there anyway so I can shut it if i need to service the sump or in case of emergency.

Kaiser,
I came across bulldog's overflow too, but somehow it didn't click. just little things like how am i ginna 'mount' the box... I did like his intergrated Durso pipe in the box 

You're right about less part in the tank with http://www.aquariumlife.net/projects/di ... ow/120.asp
I have to imagine how it work ... so the T is where my water cutoff line is, right? not where the end of the PVC intake in the tank is.
What determent the cutoff line?


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## KaiserSousay (Nov 2, 2008)

> so the T is where my water cutoff line is, right?


Yup, you got it..mine worked quite well..just noisy..
For bulldoggs setup, I used a large fish bagger box from Dr.F&S..drilled it for 1 1/4 bulkhead..it has a lip on it to hang on the side of a tank..think it was about $7..


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## boredatwork (Sep 14, 2007)

If you use the specimen box for the overflow box I would buy an extra one since they are cheap enough. They are pretty easy to crack when drilling through them.


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## KaiserSousay (Nov 2, 2008)

> pretty easy to crack


Right you are..I put the box, inverted, on a 2x4 to partially drill..got about 1/4 thru.. then turned it over to go all the way..
Slow and steady, watch out for heat, don`t push to hard, let the tool do the work.
Oh yeah, did I mention it WILL make noise :-? The pretzel that is..gurgle,gurgle,gurgle,slurrrrp,gurgle


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## captevo (Feb 4, 2008)

lol pretzel.
dos bulldog overflow make noise?


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## hidenseek (Nov 13, 2005)

Just thinking again here. Maybe someone tried this or could shed some light on the idea.

My idea here is a Vortex Eliminator. (In my own words and thinking) The concept is more adapted on a pump suction. As the water gets sucked in without a Vortex Eliminator it creates a vortex (swirling tornado) and sucks in air and causes the pump to lose efficiency and go airbound. However, by placing a plate in the intake it helps prevent this from occurring.

This is just my interpretation and may be wrong. I haven't tested this idea on the pvc overflow and may be way off, but could be something to try. I've seen similar ideas of people sticking things in the suction which helped stop the swirling actions with some success, but it severely limits the flow capacity.

Again, it's just my brain thinking again. :drooling:


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## KaiserSousay (Nov 2, 2008)

> bulldog overflow make noise


Not as bad as the pretzel did, but they will all make some noise.
That said, I got mine absolutly quiet by putting a gate valve on the line to my sump..I ran the system so the pump would run full throttle and adjusted the valve for a sump level..
Problems were a few..evaporation would change levels, meaning adjusting the flow..stopping the system for water changes/cleaning was a real chore, more adjusting..
Did a great job of cleaning, aireation, and bio colony, but ended up being more trouble than it was worth to me.
Ended up with a pair of canisters and am enjoying my tank alot more..next tank will be reef ready, pre drilled for use with a sump and will build a stand for the wet/dry.
If you build it, good luk to ya.


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## dreday (Oct 12, 2007)

it could work. but i see the vortex getting pulled past it. i built my own pvc pretzel but never used it. the only true way to eliminate the gurlge is to have enough flow to the drain. if that happens then the vortex should stop.

also tilting the top so it is at an angle will help also. maybe adding a 45 degree elbow near the water line. that way the air has a place to get sucked in with out forcing water around.


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## mel_cp6 (Feb 3, 2009)

to significantly reduce the gurgling noise, just put a drilled cap and put an airline 
in there and lower it until the noise is gone. i did this to both my 1" drain and both
no longer have the gurglin noise.
also 10gl is fine but if you have a bigger sump area, you have more room for error.
meaning you can lower the drain inlet to maybe 1" below water line instead of 1/2". 
this way when your turn off the pump, your sump can handle more water.
just my opinion.

i have a 125 gal w/ 30sump and if i had to do it all over again, i would've gone with
a 40 gal sump so i can have more volume in the sump.

btw, do not put the check valve directly onto the pvc elbow. use an airline tubing then
put the check valve. this way when the check valve need to be replace you wont have
to remove it and the glue/silicone from the pvc.


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## boredatwork (Sep 14, 2007)

KaiserSousay said:


> next tank will be reef ready, pre drilled for use with a sump


Unfortunately I realized the same thing too late as well. This is really the only way to be able to build a quiet sump.

hidenseek, in my opinion the concept you are showing is the same as almost all noise reducing contraptions - trying to limit the amount of air that gets sucked into the pipe. The problem with these approaches is that they can only make it quieter, and in doing so reduce flow rate efficiency. They will never make the noise go away.

Having said that I think this could work. The problem is that I don't think it would work the way you are thinking. Here is why.

With your plate design, you are reducing the size of the drain opening. This limits the max flow rate into the drain pipe. Now, if the drain output is not restricted, then the max flow rate of your drain pipe is the same, but with a reduced input flow rate. In other words the flow rate of the drain stays the same but the amount of water entering the drain is reduced. See where this is going? With less water filling the drain, something else has to fill the leftover volume of the drain pipe. Unfortunately this is going to be air - which is the very problem you are trying to solve.

Lets consider an example. Assume a 1" drain pipe with a max flow rate of 600GPH. Assume that the return pump is operating at 400GPH. This is not exactly correct thinking, but that means there is something equivalent to 200GPH empty space in your pipe. Without thinking about it too much lets say that at 600GPH the 1" drain pipe is completely full of water. At 400GPH, or 2/3 of 600GPH, the 1" drain pipe is 2/3 full. So that means 1/3 of it is not full - or at least not with water, but it is full of air. If you limit the amount of water flowing into the drain pipe, lets say from 400GPH to 300GPH, now the drain pipe is only 300/600 = 1/2 full or water, and so it will be 1/2 full of air.

The catch is that if the reduced flow rate at the input of the drain pipe is still greater than your pump return flow rate, then I don't think there will be any difference from adding the plate.

Now, the reason I said it could work is if instead of thinking of it as a plate, think of your picture as a cross section of the drain pipe. If that were true, then it would be successful. Why? Because instead of filling the "extra space" in the drain pipe with air, you are filling it with the crosshair. This reduces (or possibly eliminates) the amount of air that has to be sucked in to the drain pipe, reducing (or possibly eliminating) noise.

The problem is I have never seen pipe like that sold, and I think it would be pretty close to impossible to make it on your own.

Incidentatly, this is the very concept behind using a valve in the drain line to the sump - reducing the empty space in the drain pipe. Of course in a non drilled tank this is a challenge because the siphon mechanics are different which introduces some complexities. And it would require the use on an emergency drain.


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## moto_master (Jun 23, 2006)

boredatwork said:


> Now, the reason I said it could work is if instead of thinking of it as a plate, think of your picture as a cross section of the drain pipe. If that were true, then it would be successful. Why? Because instead of filling the "extra space" in the drain pipe with air, you are filling it with the crosshair. This reduces (or possibly eliminates) the amount of air that has to be sucked in to the drain pipe, reducing (or possibly eliminating) noise.
> 
> The problem is I have never seen pipe like that sold, and I think it would be pretty close to impossible to make it on your own.


If you just use a smaller pipe to begin with, there won't be as much need for air to enter the pipe...

Then again, think about when you let the water out of the bath tub. Way more water needs to flow through the pipes than the pipes can handle. The water in the tub automatically starts swirling, and then sucking in air and gurgling. I don't think there is a simple fix to making it silent.


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## captevo (Feb 4, 2008)

All good reading info. Thank you all.
I'm running a HOB and a XP3 in my 55gal currently, it hums but only when you're next to it.
Noise is to be expected.
But then again....
I found a deal on a 90gal tank. 
If it's not leaking, I'll pick it up tonight.
Your 125gal is using 30-40 gal sump, I guess I can go with the that size.
If I get that 90gal, I'll come back with DIY background questions... LOL.

Help me... the addiction...


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## boredatwork (Sep 14, 2007)

moto_master said:


> If you just use a smaller pipe to begin with, there won't be as much need for air to enter the pipe...
> 
> Then again, think about when you let the water out of the bath tub. Way more water needs to flow through the pipes than the pipes can handle. The water in the tub automatically starts swirling, and then sucking in air and gurgling. I don't think there is a simple fix to making it silent.


That's why you can't use a smaller pipe. You would get a spill.

This is a little off point, and has been pointed out several times, although that applies to most of the things we discuss. A bathtub, or toilet is not always a good example.

The reason is that in a bathtub there is always a vent. When you have a vent, air will always get sucked in, regardless of pipe size, water flow, etc. For example in your analogy you are thinking of a specific scenario in the bathtub when the water level is low enough that air cant be sucked in through the drain. But how about when there is 12"of water in the tub? In that scenario there is not a 12" high vortex sucking in air from the surface of the water. At least not in any bathtub I have seen. That would be cool though. In reality all bathtub drains have at least one source of a vent, where air can be sucked into the drain pipe. The vent exists for reasons other than draining water.

The reason I say its not the best example is that it leads to the assumption that all water going down a drain must have a swirling vortex sucking in air. This is simply not true. In fact, when a drain is designed to allow air getting sucked in, it is not working efficiently.

In addition to the bathtub, you need to think about another example. And that is what is sometimes called a true siphon (although that is not really an accurate name). The most relevant example for this is water changes. When you empty water out of your tank you use a "pipe" that takes water out of your tank without any air in the pipe. That is what is meant by a true siphon - a drain without air in it. This kind of drain will have a significantly higher max flow rate than a drain with a vent. Usually its about 600GPH for a 1" PVC drain with air, and about 800GPH for a true siphon 1" PVC drain.

So its not just noise, but also flow rate efficiency. Without air in the drain pipe you can carry a lot more water. So there is a premium put on making a drain a true siphon. It will increase max flow rate and get rid of the noise.

Now, this can be done. But in order to do it you need to be able to control the actual flow rate through the drain pipe such that you can make the actual flow rate of the drain pipe equal to the actual flow rate of your pump return. In this scenario you are reducing the maximum flow rate of the drain pipe to be the actual flow rate of the pump return. When the flow rates are equal the drain pipe is full of water, so there is no need to suck in air. It will be very quiet.

Lets use another silly example. Lets assume a 1" drainpipe with a vent. The rule of thumb is 600GPH. But that is really 600GPH of water. From the rule of thumb for a true siphon the real flow rate is 800GPH for a 1" drain. So lets say you are using a 600GPH pump. That means you are draining 600GPH of water and 200GPH of air - to add up tot he 800GPH flow rate of the 1" pipe. Now, lets say you have the same 600GPH pump, same 1" drain pipe, but without a vent. Since the max flow rate of the 1" pipe is 800GPH, but the pump is 600GPH, even without the vent, the drain will still have to suck in 200GPH of air (although its not that straightforward). But, if you restrict the 1" drain pipe to 600GPH, then that is 0GPH of air that will be sucked in.

The problem is how do you implement that kind of fine grained control over the actual flow rate of the drain pipe? The best answer I have seen is to eliminate the vent in the drainpipe and use a valve in the drain pipe return to the sump. Using the valve you can control the max flow rate of the drain pipe. However, the problem here is that in restricting the max flow rate of the drain line, you are playing a game with chance. Once you equalize the drain pipe flow rate and the pump return flow rate, there is a very good chance that they could become imbalanced. On one side of the imbalance, the pump return flow rate drops below the drain pipe flow rate, air is sucked into the drain, and you have noise. On the other side of the imbalance the drain pipe flow rate drops below the pump return flow rate and you have a spill. That is why in this method it is highly recommended to use an emergency drain.


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## boredatwork (Sep 14, 2007)

captevo said:


> All good reading info. Thank you all.
> I'm running a HOB and a XP3 in my 55gal currently, it hums but only when you're next to it.
> Noise is to be expected.
> But then again....
> ...


The noise from an HOB is different than the noise from a sump drain pipe.


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## mel_cp6 (Feb 3, 2009)

*guys, use a drilled cap with an airline tubing inside and this will reduce/eliminate the gurgling sound.*


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## I3lazd (Dec 29, 2008)

what do you mean run the airline down to the wet/dry inside the drain tube? do you have a pic of yours?


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## captevo (Feb 4, 2008)

sO,
I picked up a 90gal. It came with a aquaclear wet/dry filter sump, overflow box (loose bulkhead)
It looked like 1 inch. I think it'll be too much for my pump which is rated at 580gph and 400gph at 4ft (my tank height).
I think I'm still going to try the PVC overflow and your tip to use a drilled cap with an airline tubing inside.

What do you guy think? should i stay with the overflow box? it is really nice though.
It also came with some kinda skimmer... This was a saltwater tank and been sitting around. salt built up is a pain to clean.. any tip on that?

Update: It is 1" inner tube for the overflow box bulkhead


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## I3lazd (Dec 29, 2008)

pics??


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## mel_cp6 (Feb 3, 2009)

drill a hole on the 1" pvc cap, 
put cap on the pvc overflow vent.
insert an airline hose in the hole of the cap and 
lower it until the noise is gone.


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## boredatwork (Sep 14, 2007)

mel_cp6 said:


> *guys, use a drilled cap with an airline tubing inside and this will reduce/eliminate the gurgling sound.*


In my opinion this is the same as all of the other "fixes" out there. It does not eliminate noise, just reduces it. For some people that is OK. But a lot of people have tried these noise reducing methods with unsatisfactory results. That is the very reason this topic reappears every few days.

I am not saying any of these gurgle stopping methods are bad, they are just not for everyone. So just a warning that depending on what you are looking to achieve you may not be happy with the results.


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## Charlutz (Mar 13, 2006)

captevo said:


> sO,
> I picked up a 90gal. It came with a aquaclear wet/dry filter sump, overflow box (loose bulkhead)
> It looked like 1 inch. I think it'll be too much for my pump which is rated at 580gph and 400gph at 4ft (my tank height).


You're thinking about this backwards. The overflow CANNOT (in almost all instances*) be too much for the pump. As long as it can drain faster than the pump can fill, the overflow will only drain what the pump puts into the tank. The pump CAN be too much for the overflow and will overwhelm it until the tank overfills, but not the other way around. Use your overflow box and your pump and you will be fine.

*The only time an overflow can be too much for the pump is that if there is not enough water going through the siphon tube of an overflow, microbubbles can collect and eventually break the siphon if not monitored.


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## dreday (Oct 12, 2007)

be careful with the airline tube. i used to use this too, just with out the cap. it can get suction and actually drain water. crazy i know but i have seen it happen. something with the pressure dropping and plop water comes out

it can help but can be fatal. i think they best way is to tilt the intake. i dont know why they dont build them that way to start. if you can add a 45 or 90 elbow and see what happens. it should help a lot as well with out causing more problems.

i have nothing on mine now since i used a larger pump. another way i have seen a fix is to add a ball valve to the drain pipe. closing it slightly will cause the water to fill up enough to stop the gurgle. but it can clog up too and overflow. pros and cons to everything 'quick' fix.


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## acrosstic (Mar 24, 2008)

I used a design I found on monsterfishkeepers. I can no longer find the design plans.

I will explain it a bit here.

The design is like http://www.aquariumlife.net/projects/diy-overflow/120.asp in a few ways, but with added improvements. It acts like an overflow and not a siphon.

What you will need:
1" Pipe
2" Pipe
5 - 1" Elbows
1 - 1" T
1- 1" Cap
1 - 2" Coupler
1 - 2" Cap
1- 1" Ball Valve (Although I never use it)
1 - 1" to 2" Reducer Bushing (Modified)
Next time I would add - The airline such as the one above for easy prime (Mine are a bit hard to prime)

The basic design is the same, except the 1" PVC in the tank is inserted into a 2" Pipe.

This is achieved by cutting the bushing in half to allow a 1" pipe to slip through it. Then, insert that into the 2" Coupler attach the other end of the coupler to the 2" Pipe that is as long as the depth of your tank with a 2" Cap at the bottom.

Also, it is better if the T is as low as possible, the water will flow more easily.

The 1" Cap I didn't glue, and nothing inside the tank is glued. I drilled a small hole into the cap to allow it to suck air, but very little. This changed it from sounding like a constant toilet flush to be very quiet.

The vent should be higher than the water level in the tank because if the water gets clogged running to the sump, you want the water to backup back into the tank not over the vent and onto the floor.

The bushing not only acts as a guide for the 1" pipe, but it also as the vortex eliminator that has been discussed here.

I made two to handle my Maddrive 12 return. One can handle it, but redundancy in case of a clog. Seems like my pump would overwhelm them, but it doesn't. Probably due to head loss and I might also be restricting the return with my custom spray contraption.

I don't love these units. I am going to drill my new glass tanks and make internal overflows. I suggest doing the same if you can. a siphon or PVC overflow is never going to be as good as the real thing.

I will say they have worked very well for the past year. The only trouble is priming them, which I believe would be fixed with airline attached.


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## mel_cp6 (Feb 3, 2009)

> be careful with the airline tube. i used to use this too, just with out the cap. it can get suction and actually drain water. crazy i know but i have seen it happen. something with the pressure dropping and plop water comes out


thats probably because the vent is equal or lower than the intake drain.

this can not happen if the vent is higher.


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## I3lazd (Dec 29, 2008)

Ok I can settle this whole debate right here and now here is my overflow and there is absolutely no gurggle or any other sound it makes very quiet and efficient. I think pics will describe it best.









It is a 1" pipe as you can see it has a t on the end and has a drilled cap on the closed end and then a 90 for the water to go into.








a pic from above of the small hole drilled in the cap.


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## dreday (Oct 12, 2007)

yea those are the best. durso standpipe. also your tank looks drilled. not exactly what the op was getting at.


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## I3lazd (Dec 29, 2008)

My bad thought it was drilled should have looked a little harder.


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## I3lazd (Dec 29, 2008)

what if you made something like Wayne DesLauriers and built an overflow pvc as shown here then just add on the t to put on the cap and drill it, not sure if it would work but it seems like a good idea.









he created a a siphon that went into the pvc and capped the bottom of the pvc so it would fill to the overflow line then go down i'm sure this would solve your prob. do a search from the homepage for DIY - How to Make an Automatic Water Change System for exactly how he did his,I'm sure it would be easy to improve on.


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## parkayandbutter (Jan 15, 2008)

Here is what you need. Simple as it gets and at a price that is just as low as you can get.

http://cgi.ebay.com/Aquarium-Overflow-B ... dZViewItem


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## I3lazd (Dec 29, 2008)

no s*** but if his tank is tempered he cant do that unless he drilled out the side out the tank where it isn't tempered he could run a durso pipe out the back of the tank and just have the 90 in the tank. Not sure if tha would work but I doubt the bottom piece of the tank is not tempered almost all new tanks have tempered bottoms and it will shatter if you were to drill.


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## boredatwork (Sep 14, 2007)

parkayandbutter said:


> Here is what you need. Simple as it gets and at a price that is just as low as you can get.
> 
> http://cgi.ebay.com/Aquarium-Overflow-B ... dZViewItem


Stop posting that. It is garbage. Not only is drilling not something most people want to do, but it will not be silent.


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## boredatwork (Sep 14, 2007)

I3lazd said:


> Ok I can settle this whole debate right here and now here is my overflow and there is absolutely no gurggle or any other sound it makes very quiet and efficient. I think pics will describe it best.


Well, I would agree it can be made quiet, but it will still have some noise - not in the overflow but in the sump.

And yes, things like this illustrate why a drilled tank is a good thing if you want a sump without the noise.


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## boredatwork (Sep 14, 2007)

I3lazd said:


> what if you made something like Wayne DesLauriers and built an overflow pvc as shown here then just add on the t to put on the cap and drill it, not sure if it would work but it seems like a good idea.
> 
> 
> 
> ...


If it has a vent it will make noise. There is no way around it. If the overflow mechanism has a vent then it will not be quiet. You can muffle the sound with some other tricks but the noise will not go away.

In order to make it quiet you need to find something that does not have a vent.


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