Hole in the side of a durso pipe?

[Antegon]

My corner overflow durso came with this hole drilled on either side of it near the top. I haven’t seen that before, does anyone know what this is, for noise reduction or redundancy maybe? Please advise


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[mcgyvr]

Antisiphon hole

To stop a backfeed situation that develops when the power goes out and the water drains back into the sump because of the siphon formed..
The hole will let air in this stopping the siphon..

That must be from a system where the return is in the overflow and not an over the top return or that would just make a damn mess

[ericarenee]

Since there is a air tub in the top i am not sure why thy drilled this out.I would assume to allow more air into the tube to increase water flow but would be at the cost of a lot of extra noise in the sump..

I Have seen this before But never tried to see any benefit

[ca1ore]

On a return it would be an anti-siphon hole, but not on a durso drain pipe. My prior ML265 came with drain kits like this, with the holes on the sides. Pretty standard actually; though I remain unclear as to the precise purpose. It may be to ensure sufficient venting if you approach the theoretical limit of the drain (at which point the airline vent is insufficient). Otherwise, it seems to make little difference one way or the other.

[Antegon]

Great, thanks for the info!
Yes, the corner overflow holds the return and drain. It’s a shame, there is room for another bulkhead for a herbie/some sort of dual drain, but assuming it’s tempered now and/or drilling pressure would be dangerous so close to the other drilled holes.
Maybe remove the return line from the overflow section, use its bulkhead to run the second drain for the herbie, and run the overflow up and over the back?


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[nereefpat]

Originally Posted by Antegon

Maybe remove the return line from the overflow section, use its bulkhead to run the second drain for the herbie, and run the overflow up and over the back?


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You betcha!

Use the smaller diameter hole for the syphon and the larger one for the emergency.

[Antegon]

Great, feeling good about that plan!
Thanks!
Is the herbie system quiet, or is it really only the beananimal that will silently run?


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[Antegon]

Also, gonna have to get creative with the glass lid with that return over the side, wonder if you could etch a space in the side of it...


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[nereefpat]

Originally Posted by Antegon

Is the herbie system quiet, or is it really only the beananimal that will silently run?


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My herbie is silent. Herbie just doesn't have the ability for the emergency/trickle to turn into a syphon.

Originally Posted by Antegon

Also, gonna have to get creative with the glass lid with that return over the side, wonder if you could etch a space in the side of it...


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I bet the glass lids are tempered, so you won't be able to alter them. I would ditch the glass lids, personally.

[Antegon]

Originally Posted by nereefpat

My herbie is silent. Herbie just doesn't have the ability for the emergency/trickle to turn into a syphon.







I bet the glass lids are tempered, so you won't be able to alter them. I would ditch the glass lids, personally.

Cool. Herbie design it is, then!
Do you go lidless? I’ve built a full canopy, and thought the glass would do well to help dampen the sound from the overflow, as well as keep any jumpers at bay.

(This is the sump design I’m aiming for that this overflow will serve, although still gathering info)
Custom 29g sump plans for your approval
https://r.tapatalk.com/shareLink?sha...5&share_type=t


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[nereefpat]

Most of us don't use glass lids. They trap heat, block gas exchange, and block light. That isn't to say glass lids CAN'T be used.

Some of us use mesh lids. This is especially recommended for tanks with jumpers.

Your sump is way more complicated than mine, so I won't be much help there. One thing, related to your new overflow/drain plan, is to have your drains enter the water just under the surface, but no more than an inch.

[Salty Waffles]

On the All Glass/Oceanic Dursos that came with my tank, from what I understand the holes in the sides help start the drain quicker. Or so they say....

If you have noise from your overflows with a Herbie setup, try raising the Herbie standpipes to within a few inches below the top of the weir.

On my tank (RR All Glass 125) I set the full siphons about 4 or 5 inches below the weirs with the emergencies a set a couple inches over the siphons. My overflows are silent.

There is a very helpful video here if you search for "dual herbies".

[ca1ore]

Originally Posted by Antegon

Great, thanks for the info!
Yes, the corner overflow holds the return and drain. It’s a shame, there is room for another bulkhead for a herbie/some sort of dual drain, but assuming it’s tempered now and/or drilling pressure would be dangerous so close to the other drilled holes.
Maybe remove the return line from the overflow section, use its bulkhead to run the second drain for the herbie, and run the overflow up and over the back?

The bottom may well have been tempered after it was drilled - plus there isn't really enough room to safely put in another hole. One option, other than a HoB return, is to bore a hole in the back glass that is contained within the overflow. You'd have to determine that the back isn't tempered, of course, but I did this a few times as a way to avoid an over the back return but still get the advantages of a siphon drain.

[Antegon]

Originally Posted by ca1ore

The bottom may well have been tempered after it was drilled - plus there isn't really enough room to safely put in another hole. One option, other than a HoB return, is to bore a hole in the back glass that is contained within the overflow. You'd have to determine that the back isn't tempered, of course, but I did this a few times as a way to avoid an over the back return but still get the advantages of a siphon drain.

Great, thanks for the tip. I assume seeing if the glass is tempered is just a check with the manufacturer, as there doesn’t seem to be a visible difference, unless I’m missing something, which would not be new haha.


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[nereefpat]

You can check if glass is tempered using polarized sunglasses. It will be quite obvious if you know what to look for.

[tank o tang]

My guess is that it is a homemade durso and the person that made it was probably using just the standpipe at first and was getting drain sounds. They probably read about the need for air to escape and drilled the holes because the one on top wasn't cutting it.

[Antegon]

Can’t find any sign of the manufacture (just a sticker with a “made on” date). Thinking I’m gonna play it safe and convert the two bulkheads to a herbie and run the return over the side and back out the overflow into the lock line. Worried about the flow restriction of the double elbow required on the return (was gonna run a 3/4” PVC line).
Trying to research that now.


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[gargoylenest]

not home made. got the same hole on mine. probably u got a marineland like mine.
no idea what its for, but I leave it like this because I don't tend to repair something unless its broken.

[Antegon]

Originally Posted by gargoylenest

not home made. got the same hole on mine. probably u got a marineland like mine.
no idea what its for, but I leave it like this because I don't tend to repair something unless its broken.

Ok cool, thanks. Do you have any noise issues?


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[gargoylenest]

only the water splashing in the sump from the drain. But did a reverse durso and fixed the issue by 90%. and since its a my fish room, I don't care about having 100% silence

[Antegon]

Originally Posted by gargoylenest

only the water splashing in the sump from the drain. But did a reverse durso and fixed the issue by 90%. and since its a my fish room, I don't care about having 100% silence

Good to know. Ty!


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