Who can tell me why my overflow does this?

Jenn, I was at Shane's this morning and his drain line is at a constant fall. I am pretty certain it is a matter of not enough air but not having had one before I just don't know for certain. I will say that when I got there, he had it adjusted so that it never went into a complete siphon. But, it woud draw down enough that it would suck air in through the holes in the side of the stand pipe that I assume are intended to break the siphon during a power outage. Because of that, we tried lowering it some and then it would go into full siphon.
 
The drain is gravity fed, not a siphon. The Durso is just a way of quieting it (when it's dialed in).

The whole power-outage-siphon-break applies to the return pipe (a whole other post).

Well if the drain is pretty much a straight shot to the sump, then it's likely that the breather nipple on top of the Durso just needs to be widened/enlarged a bit.

Jenn
 
grouper therapy;774364 wrote: What size was that return pump?

It's 850gph.

JennM;774408 wrote: Make sure the drain hose goes down, not down, up and then down and that may resolve the problem ... if that's what the problem is.

I spun the sump around for that reason when I first installed it. Now the hose is stretched out, but there's still a slight dip in it caused by the weight of the water. When I support that dip with my hand, it does seem to help. But the problem never completely goes away.

I'm going to play with it some more...
 
When I had my 75 with the hob overflow I ran a modified durso. If you LQQK back at my first build you will see the turned down 90 is not connected at the bulkhead. I braced the turn down and it LQQKed like a 180 bend. I the offset it about a 1/2" back to allow more flow. I had a 1/4" tube coming out of the top

Hth

I had a mag 7 on mine and would never valve a pump back if needed I would open the bypass up and reduce the flow that way.
 
I had the same issue with my 60 gallon cube installed a ball valve and it resolved the issue!
 
Ball valves in the drain line scare me. To much chance of something getting caught in it that could cause an overflow. In a bean animal, you have three drain lines so the ball valves are not a big issue. Two of them are wide open at all times with only one throttled back. In a Durso you only have the one. If that plugs, you are going to have an empty sump and some wet floors.

Edit:
JennM;774416 wrote: The drain is gravity fed, not a siphon. The Durso is just a way of quieting it (when it's dialed in).

LOL Yup, brain *&^% on my part there. :) But now that makes me wonder. This is the first time I have looked at one closely. In this case at least, there is a riser pipe with a tee at the top. The tee is capped with a small air inlet. The branch goes to a 90 deg fitting pointed down with a strainer on it. That all makes sense to me. But, the riser pipe has 3 holes that are maybe 1/4" just below the tee. What is the purpose of those holes? When adjusted down enough to stop the full siphon, these holes slurp air. When raised enough to stop the slurping the drain goes into full siphon.
 
The valve wouldn't go on the drain. It would go on the pump to throttle it back.

It shouldn't be necessary though. Widen the hole on the Durso, that will probably solve the problem.

On the Durso, it doesn't matter if you slide it up or down, the water will drain from the same position on it. Look more closely. It's not a siphon, and adjusting the drain pipe upward or downward (it's an AGA kit with a telescopic Durso-style drain pipe) will only change the water level in the overflow box, not where on the pipe the water drains. Adjusting it up or down may quiet it some - higher will give the water flowing over the overflow a shorter distance to fall (and less trickle/splashing sound).

Just widen the hole - if that doesn't solve the problem (which it should) it won't create a new problem.

Jenn
 
They're not talking about ball valves in the drain line, though, are they? I'm thinking they mean a ball valve between the return pump and the return line. If that got clogged, everything would simply stop once the water dropped to the level of the drain holes, right?

The more I read, the more I think it's a flow problem. I think the return pump is pushing more water than the drain can handle. When it gets too full, the flush happens.

Jenn (and anyone else for that matter), do you know what the corner overflow for the 90g Aqueon All-Glass is rated at? I can't find it anywhere -- either on the box, their website, or a Google search.

Edit:
JennM;774476 wrote: Widen the hole on the Durso, that will probably solve the problem.
That's not helping. As Rich suggested, I spent some time forcing air into that hole to increase the air flow. Didn't help.
 
It should handle 650 gph. Your pump is rated 850 gph at 0 feet, but should be about right at 4 feet which is about where it pumps to from the sump to the top of your return pipe (I know what I'm doing in that regard ;) )

If the pump was too much for the drain, your tank would overflow. The drain wouldn't be able to drain it but it would be pumped into the tank so the result would be a dry sump and water on the floor over the top of the tank.

Shouldn't be able to happen with that pump.

Have you tried drilling out that hole a bit yet? :)

Jenn
 
The drain can</em> handle the flow, just not quietly. Devil's advocate: why would Aqueon have a drain pipe with a hole that was too small? Isn't that something they would catch and fix?
 
Alright, I've changed my mind on flow rate being a problem. At a 5' head (3' of hose plus 2' of return pipe in the overflow), the graph on the box says the return pump is pushing just under 500gph. That should be well less than what the overflow can handle.

True, cranking it down might solve the flushing problem, but I should be able to handle 500gph of flow, right? I don't want to reduce the flow just because I can't figure out how to tweak the drain to get it to work correctly.
 
I think the answer has been given several time... enlarge the vent hole on top of the Durso.

If: the drain is only about 1" under the water...
And If: you have no dips in the drain line...

What do you have to loose? Enlarging the vent hole will not have a negative effect.

.
 
The holes on the side serves several purposes. I know I’m going to say this wrong but here goes.

The water flows down the inside of the pipe slowly. The faster it gets the louder it gets and needs air to allow it to regulate the flow. Cut the air off and its turns into a full siphon and then you get the flushing. The drain can handle a lot more flow than you think. And the extra holes on the side allow for more water to flow and is also a snail guard and a vacuum brake for when the pump is off.

The bean animal has 2 main drains. A full open sorta like the durso, and a full siphon that’s adjusted with a valve. The first one is not enough and is a pain to adjust, like you’re having. The 2nd one is valved back just to keep the water level in the overflow box where you want it, about mid-point in the street elbows.
Open too much and it starts flushing. Closed too much and the water will rise as it’s not going down fast enough. And then you have the 3rd one, the emergency one. It’s only used at startup. Then it stays dormant until something goes wrong. You also have to have the pipes no more or less than 1”+/-. This helps the no noise in the sump and too deep has too much back pressure. The 3rd one does not matter.
 
elFloyd;774519 wrote: I think the answer has been given several time... enlarge the vent hole on top of the Durso.

If: the drain is only about 1" under the water...
And If: you have no dips in the drain line...

What do you have to loose? Enlarging the vent hole will not have a negative effect.

.

Amen.

Shane - not everybody encounters this issue. But for those that do, the fix is pretty simple.

Jenn
 
I had the same problem and choked my flow down to a trickle. I talked with Jenn about it on Sunday, removed the air line as she instructed and now I have my return pump at full blast and no flushing at all.
 
grouper therapy;774517 wrote: try raising it up a little

Raising what up? The top of the durso? I did raise it as high as I could, and it's definitely better the higher I raise it. I just can't raise it high enough to make the flushing go away without the tank overflowing.

JennM;774535 wrote: Shane - not everybody encounters this issue. But for those that do, the fix is pretty simple.

Before I go drilling a $60 piece, I do want an answer to this question from earlier: "Devil's advocate: why would Aqueon have a drain pipe with a hole that was too small? Isn't that something they would catch and fix?" :)

I really want to understand how it works and get it to work correctly, not just rig it -- just like I didn't want to put a ball valve on it to reduce the flow until the problem stopped without actually addressing the real issue. I have no problem making the hole wider, but I don't want to do that until I know that in my particular</em> setup, the hole just needs to be bigger -- that it's not actually something else and making the hole wider just covers it up.

And before I do anything else, I'm going to get some PVC and elbows to replace the flexible tubing -- making sure that the water flow is always downhill, not even flat. There's still enough uphill and</em> flex in that line to make me believe that that has at least a little to do with it, and switching to PVC isn't going to hurt anything.
 
ShanePike;774550...And before I do anything else said:
and</em> flex in that line to make me believe that that has at least a little to do with it, and switching to PVC isn't going to hurt anything.

I would think that adding elbows and pvc instead of a straight shot slightly curved flexible line would make the flow worse...I am not an expert however.

When I was talking about adding a "gate" valve (not ball valve) to the drain line, I was speaking mostly to theory, and not to practical application. Seems your durso does not handle the flow with the added turbulence that air adds to the drain, but that when the column of water rises enough to create a pure siphon, that the drain auto corrects. In theory, removing the durso from the system completely and slowly adjusting the gate valve closed would cause the system to finally reach full siphon. further adjustment would create a near permanent full siphon where there was about 6-8 inches of water above the bulkhead, so no air was being sucked into the pipe, and the siphon maintains this. as the pipe becomes slimed with algae, etc. it may slow the flow slightly, but then the water in the overflow would rise to 10 or so inches above the bulkhead, and the added head pressure of the water column would force even more water though the drain.

IF there was another hole to plumb in an emergency drain, that would create another full siphon pending the failure of the bulkhead drain, then you would have a back-up. I know my posts were a bit more experimental, and by no means was I suggesting you do it, therefore my posts were probably better suited for a different thread. Sorry about that. It's just your video of back-up to full siphon...rinse and repeat piqued my interest.

That all being said, just because a pump is rated at X flow with X head, does not mean that is exactly what you will get, and just because a durso is rated for x drain volume, it will really depend on several things, such as drain hose size, turns, etc.

Adding a ball valve, or for a few bucks more a gate valve should solve your issue, without removing too much flow at all. In fact, you may be only a few gallons per hour too high. An added benefit of throttling a pump is sometimes it makes the pump more silent as well. I know my previous posts contradict this, but if it were my tank...I would throttle the pump, and not the drain...I was just waxxing theoretical :)

CJ
 
I don't know the answer, Shane, other than maybe they don't know about the problem. It doesn't happen to everyone, in fact it happens to very few.

WBeacham has a Marineland overflow kit and I believe its prior owner had put a little piece of tubing in the hole (ML kits just have a hole, they are made out of regular PVC not specially molded plastic like the AGA/Aqueon kits are). Same issue, same fix.

I wouldn't bother with the trouble of PVC and elbows but if you feel like you must do that, don't get 90 degree elbows, get 2 x 45s to achieve the corner, it works better. Still, you're better off getting a shorter "vacuum" hose (call it that because it looks like the hose on a vacuum cleaner, not because it actually vacuums).

Before you fuss with all that, just widen the hole already. If you find it messes up the assembly, I'll give you a new piece. That assembly is made of several pieces that snap together, you're only 'risking' one little piece.

Putting my money where my mouth is, that ought to fix it.

Jenn
 
JennM;774561 wrote: Still, you're better off getting a shorter "vacuum" hose (call it that because it looks like the hose on a vacuum cleaner, not because it actually vacuums).
The hose is actually just right. Could be a hair shorter, but the problem is really the span. It's stretched "taut" about 2.5 ft. The weight of the water ensures that it's always bowed in the middle, though. Hard PVC would solve that. (And yeah, I was definitely planning on avoiding right angles.)

JennM;774561 wrote: Putting my money where my mouth is, that ought to fix it.
Ha! Indeed. I'll get my drill :)
 
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