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View Full Version : Making a Ghost Overflow Silent


ca1ore
10/04/2017, 07:59 AM
..... and I mean silent; as in no noise at all. If something makes noise, then it's not silent ..... it's just quiet.

Anyhow, looking to hear (and share) any tips folks might have. I'm test running my MM overflow (that it is MM is immaterial as all the manufacturer models are the same in their essential function). It's my first ghost style overflow, having lived with corner overflows for the last 27 years :(

Noise comes from four places: sound of water trickling into the skim box, sound of water pouring into the external box, drain sucking and water entering the sump. In my case, the sump is in my basement so not an issue. Drain sucking is easily accounted for by properly tuning the siphon. But how to address the trickling/pouring sounds. Thus my essential question of how high in the two boxes are folks running the water level? My MM overflow did not come with any internal plumbing so I made my own U tubes. I've played around a bit with the height of those U tubes, but not yet achieved silence.

My overflow did come with a cover for the internal skim box, but I'm not inclined to use it because it short circuits the last line of overflow defense in the event of some kind of major blockage. I will use the external covers, which helps to damp most of the pouring sound.

jacksonpt
10/04/2017, 08:43 AM
Are you looking at this strictly from a plumbing perspective? Changing flow rates could have a meaningful impact on trickling/flowing water noise.

mcgyvr
10/04/2017, 10:49 AM
Noise comes from four places:
1-sound of water trickling into the skim box,
2-sound of water pouring into the external box,
3-drain sucking and
4-water entering the sump

3 and 4 are not an issue when you get the valve correct on the full siphon channel because its a bean system.. There is virtually no sump noise or drain sucking provided you adjust the valve and have the outlets of the pipes approx 1/2" below the water level..

There is only so much you can do with #1 and its really not much of an issue unless you are running fairly high flow rates.. The only real way to adjust that is to widen the internal overflow box (which is why at least one "MM" makes a few different sizes I believe.. I custom made my ghost because the off the shelf offerings weren't wide enough IMO).

#2 is the biggest contributor to noise IMO but the way to solve that is to ensure that the tops of the 2 elbows (basically the normal water height in the external box) are just above the lowest point of the bulkheads so that there is no water falling at all..

Just don't glue anything inside the external overflow box to start and leave the pipes a bit long and adjust down as need when you get it running...

Then it will be "silent"

Jboone82590
10/04/2017, 11:28 AM
I am interested in this also.

My problem is that when i bought my tank the guy that was helping me at the LFS told me what i should do and i only got one hole drilled in the back for the overflow.
I want to make it quiet but i believe it would be more of a headach then its worth so i think i kay just wait fir the upgrade and do it right then.

Sent from my SAMSUNG-SM-G891A using Tapatalk

ca1ore
10/04/2017, 11:57 AM
Are you looking at this strictly from a plumbing perspective? Changing flow rates could have a meaningful impact on trickling/flowing water noise.

I bought the 36" MM overflow and I have to run my PW200 pump maxed out to get about 1,200-1,300 gph though the tank. So those are fixed. Variables include futzing round with the plumbing to raise or lower the water level in the two boxes.

ca1ore
10/04/2017, 12:03 PM
3 and 4 are not an issue when you get the valve correct on the full siphon channel because its a bean system.. There is virtually no sump noise or drain sucking provided you adjust the valve and have the outlets of the pipes approx 1/2" below the water level..

There is only so much you can do with #1 and its really not much of an issue unless you are running fairly high flow rates.. The only real way to adjust that is to widen the internal overflow box (which is why at least one "MM" makes a few different sizes I believe.. I custom made my ghost because the off the shelf offerings weren't wide enough IMO).

#2 is the biggest contributor to noise IMO but the way to solve that is to ensure that the tops of the 2 elbows (basically the normal water height in the external box) are just above the lowest point of the bulkheads so that there is no water falling at all..

Just don't glue anything inside the external overflow box to start and leave the pipes a bit long and adjust down as need when you get it running...

Then it will be "silent"

Yeah, it's mostly water trickling into the skimmer box. I'm using a pair of WAV pumps with the external magnet inside the skim box and water hitting them is making the most noise. I think I can damp them with a bit of filter batting.

LQT
10/04/2017, 02:46 PM
I was gonna say... get some enkamat material to put inside the skimmer box to help dampen the noise.

http://www.glass-holes.com/Enkamat-12-x-13-enkamat.htm

ca1ore
10/04/2017, 03:26 PM
Hah, great minds! That's exactly what I used; worked perfectly.

mcgyvr
10/04/2017, 06:34 PM
pair of WAV pumps ... inside the skim box and

err..huh? why powerheads in the box?

ca1ore
10/04/2017, 07:36 PM
err..huh? why powerheads in the box?

You didn't quote the important part ... the 'external magnets inside the skim box' part, not the entire powerhead (though to be fair, I have done some hair-brained things in the past). Rear panel on my new tank is 1 1/8" and it is not clear that the WAV pumps will 'stick' to a wall that thick. So, if I am going to use them on the rear it has to be on the skim box. I may run them on the end panels which are 1" thick. We shall see.

I had the tank maker 'thin' two sections on the rear panel so I could use my pair of MP40s, but was not going to do that for the WAV pumps since I am not certain I will even need them.

Lsufan
10/04/2017, 08:55 PM
I don't have a mm but I have a similar DIY setup. I have found that by keeping the water level about half way up the pass thru bulkheads is where I find it to be the quietest. If I have the water level at the lowest point of the bulkhead I can still hear it some. When I raise it to about half way it silences the water going to the exterior box but it also raises the water inside of the wier & that helps with the water going over the wier because it isn't falling as far. Basically, the higher the water level in the boxes the quieter mine is.

Did u get the toothless version or does it have the teeth? I only ask because it would seem like the teeth would make it more difficult to get silent.

Something u could try is just put a piece of pipe in the open channel bulkhead to extend it up to where it isn't receiving any water. Then play with the water level inside of the boxes until u find it to be the quietest. Then u will know the hieght to place the open channel u tube. It would keep u from constantly having to adjust the height of the u tube until u find the water level in the box. U would also be certain the noise isn't coming from the open channel

ca1ore
10/04/2017, 09:12 PM
I got the toothy version. I arrived at the same conclusion on water levels in the external box, which meant extending the pipe on my U bends. Turns out the skim box trickling was water bouncing off the WAV magnets (which I'm not even sure I will use) and a strip of filter batting has damped the noise mostly. May be not silent, but close enough.

Thanks to all who offered thoughts.

mcgyvr
10/05/2017, 05:32 AM
You didn't quote the important part ... the 'external magnets inside the skim box' part, .
:lmao: ha.. not sure why that part didn't sink in when I read it..
That makes sense..

rhinonm
10/05/2017, 07:26 AM
I bought the 36" MM overflow and I have to run my PW200 pump maxed out to get about 1,200-1,300 gph though the tank. So those are fixed. Variables include futzing round with the plumbing to raise or lower the water level in the two boxes.

I have a 36" MM too and run 2500 gallon/hr through is with 0, zilch, no noise. The trick is to have the water level high in both boxes by raising your overflow pipe return pipe. You have 3 return pipes, 1 full siphon, 1 emergency, 1 overflow which should only have a trickle. By raising this (overflow pipe) the water level in the first box is high enough that when water enters from the tank it doesn't fall very much thus not making a sound. Make sense?

ca1ore
10/05/2017, 08:15 AM
You have 3 drain pipes

None of this 3 drains stuff (fixed your terminology) - mine has 5! Three siphons (I like to take advantage of gravity), then the standard open channel/backup siphon and the dry emergency.

I certainly understand conceptually raising the levels inside the boxes, was more curious about what levels specifically folks have found to work best.

ca1ore
10/05/2017, 12:04 PM
I have a 36" MM too and run 2500 gallon/hr through it

Do you feel it handles that amount of flow without any trouble? I won't be going up that high (actually did the math and figured my PW200 will do about 1,400 against head), but it's good to know.

rhinonm
10/05/2017, 08:28 PM
It handles it perfectly. Now I have no teeth which helps the flow too. Best style overflow I have ever used. I have my Jebao dct 15000 maxed...so it could even be 3000+ gph. Specs on the dct are 4000 gph and I'm at 4ft head using 2 1" bulkhead returns using 1" return pipe.

rhinonm
10/05/2017, 08:30 PM
[QUOTE=ca1ore;25234417]None of this 3 drains stuff (fixed your terminology)

Thx and you are correct. I wrote that at 6am before my first sip of coffee :worried2:

I raise the level in the 2nd box just high enough so there is a very slight waterfall in box 1. Thus minimizing sound.

Other thing to do is make the "Open Channel" just trickle water. I use a gate valve to dial in "Siphon Channel" so it only flows enough to slightly trickle over "Open Channel".

Make sense?

ca1ore
10/05/2017, 10:20 PM
That would seem like the right way to do it. I've run herbie style drains for decades (before they were Herbie :lol:) and always run the open channel with a trickle, even though that makes some folks apoplectic. My first BA this time around.

ca1ore
11/07/2017, 03:36 PM
Now that I have the tank up and running, I am finding that the water level in the external box is too low and I am getting a lot of falling-water noise from the internal skim box. Only running 1,400 gph. Clearly I have to raise the water level in the external box by raising the backup siphon pipe.

IdahoCindy
11/07/2017, 04:17 PM
Mine is silent. The water level in the outer box is up to within a 1/4 inch of the top of the nut that holds the box on. The pipes are very near the surface of the water. Two are open and one is a full siphon U. There is BARELY a trickle in one pipe, dry in the other. Mine is toothless and I have covers internally and externally. It's an 18 inch MM on a 210 gallon tank with a Jaebo 15000 on 50%. The set-up is so sexy it's practically on display since the tank is visible on 4 sides.

ca1ore
11/07/2017, 04:57 PM
Yeah, water level in my external box is barely half way up the bulkhead nut.

Lsufan
11/07/2017, 08:04 PM
Like I mentioned before, I find it to be the quietest with the water level about 1/2 way up the bulkhead. The flow through the box does affect it somewhat, I find the more flow the higher the water level needs to be. I have around 1200 gph through mine so that is why I need the water level a little higher. Some can get by with it just above the bottom of the bulkhead where they don’t have a waterfall, but they probably don’t have a bunch of water moving through it.

ca1ore
11/07/2017, 11:41 PM
Right, so at 950 gph, with the external box water level right at the bottom of the connecting bulkheads it was essentially silent. Increasing flow to 1450 and it was most definitely not silent. I had to increase the height of the open channel by about an inch, which raised the external box water level to about 2/3rds of the way up the bulkheads and now it is essentially silent again.