Vented Return Line why?

[bboersma79]

I just added a durso to reduce the noise on my tank. Now I noticed that the elbow on at the top of the return line has a hole in it to vent and I assume anti-siphon? Is this hole necessary, it makes a lot of noise because the water is outletting right at the top of the overflow basin waterline and splashing the water around.

My current thought is to raise my overflow line so the hole is submerged in the overflow basin but then I will only have about a 1/2" drop between the display and overflow basin?

Or could i replace the elbow without a hole? Could make a vent hole lower on the return pipe?

 

[Catharsis70]

It is antisiphon protection. A friend of mine ran an airline tube from the home to the water line in the main tank so that the water coming out falls about a 1/4". If you do this though it is VERY important to keep it clean and be sure it doesnt clog.

 

[bboersma79]

doesn't the check valve cover me for antisiphon, would this just be a secondary protection?

 

[Toddrtrex]

I personally wouldn't trust a check valve for that. Too many stories about they failing. I would consider the check valve secondary.

HTH

 

[Vincerama2]

I'm assuming you mean the Durso-like thing that AGA/Oceanic calls the Megaflow kit?

Plug the hole with your finger and you'll see that it siphons water. It's purpose is to allow the main input to be submerged (thus reducing water sound) and allow aird to get drawn down to the drain (just to balance water/air flow)

Try just attaching a piece of airline tubing to it, and route it under the tank or something.

V

 

[RandyStacyE]

I use a durso in my overflows and with that design the hole is on the top. I run my return back into the display tank and keep the return "just above" water line. In other words I don't bother with a hole in the return.

I've seen the Mega Flow design. I like their quick adjustable stand pipes! I just don't like their design for the Durso rip off.

 

[Vincerama2]

Ah, sorry, I always confuse "return line" with "drain line".

I have holes drilled in my return lines slightly below the surface of the water in my display tank. That way, if the return pump fails, the siphon will break quickly and won't suck water into the sump.

I added some more, actually, after my pump failed and the CLOGGED return line vent did NOT break the siphone and my return lines, which are submerged about 6 inches...siphoned six inches worth of water into my sump and carpet. Bah!

With the holes above the water, air would get sucked in (venturi effect) and blow bubbles into the display tank.

V

 

[bboersma79]

yeah it is the return line, I think I am going to replace the elbow and put a hole below the waterline an inch or so...that should work...

I have an Oceanic overflow but it isn't the mega since it is a corner tank, the noise from the tank is almost completely eliminated when I cover the hole...

 

[RandyStacyE]

The only problem with putting a hole 1" below the water line is that when the electricity goes out 1" of your display tank WILL back-siphon to your sump.

From what I understand you do have a check valve, but as previously stated ~ you can't rely solely on them. I personally do not value them what so ever especially since they can cause "some" back pressure. I never use them.

In a case where you keep your return 6ââ"šÂ¬Ã‚ below the water line Iââ"šÂ¬Ã¢"žÂ¢d put the hole ââ"šÂ¬Ã…"œjust belowââ"šÂ¬Ã‚ the water line (bearing in mind that it will back-siphon to that point).

 

[bboersma79]

My sump can handle the 1" overflow so that shouldn't be a problem, in reality I am only lowering the current hole about 1/2"...

 

[Roland Jacques]

<a href=showthread.php?s=&postid=6923958#post6923958 target=_blank>Originally posted</a> by bboersma79
yeah it is the return line, I think I am going to replace the elbow and put a hole below the waterline an inch or so...that should work...

In your tank or the overflow box? if its in the tank no issue. as long as you sump can handel it.

If it is in the over flow box that can be an issue.

I would leave it where is and just use a piece of your tube sponge and just zip tie under the elbow.

Check valves suck.



.

 

[beanoil]

yourfishman,
I'm not following what you meant with the tube sponge and zip tie. Could you clarify? I'm about to setup and Oceanic 58RR with the Megaflow kit, so I expect the same thing as bboersma79
mentioned.

Also, the kit that came with my tank has the dual output locline nozzle, and the overflow has two knockouts. I would assume that one nozzle would protrude from each knockout, creating flow in both directions. But the Durso-like drain takes up too much room in the overflow to allow it. Anyone with suggestions or similar exeriences? Thanks.

Grant

 

[Roland Jacques]

Also called a prefilter sponge, some protein skimmer has them on their output lines.

These are round, tube like, about 6" long. (They use to come with the Oceanic overflow kits, I donââ"šÂ¬Ã¢"žÂ¢t know if they still do or not. Oceanics are black.) You also see them in those hang on the back overflow boxes, they are white. Their made to slip over 1" tubing. Sense most return lines are 3/4" you'll need a zip tie to hold there.

The water get squirted out though the sponge and, no noise.

Thier may be a Y fitting for your locline. if so run one line out the knock out of your choise then use the Y for the 2 nozles. if your using a high pressure pump you might want concider a penductor instead of 2 nozzles

 

[beanoil]

Forgive my ignorance. What's a penductor?

Grant

 

[Roland Jacques]

it increases the current/flow that comes out of your nozzle by up to 5xs. but they work best on high pressure pumps, 20 feet rating and higher. ill look for a link

http://www.myreefcreations.com/penductor.htm

http://reefcentral.com/forums/showthread.php?s=&threadid=787202

 

[bboersma79]

that should solve the problem, will allow air to pass through the sponge and at the same time diffuse the water flow, will give ita try, thanks.