Overflow Failure

[Eman79]

I've got a glass 55g with an overflow similar to that sold by lifereef. Twice in the last 6 months, the U - Tube going over the back of my tank has somehow lost suction. Unfortunately, I've not been home either time, and have had the problem resolved by someone else, so I do not know what has caused this failure.

I'm looking for suggestions as to what may be my culprit, and also if there is a way to failsafe my overflow.

Water levels are set as to not overflow the tank if the overflow fails and the sump runs dry, but this is still obviously not good for my pump or critters. Thanks!

 

[jrp1588]

Air bubbles getting into the U-tube is a common cause.

 

[wildman926]

Air bubbles getting into the U-tube is a common cause.

Not if you have enough flow.

Or, for a fail safe option, get a pump stopper kit from Aquahub.com. You can see it HERE.

I use one on each of my tanks, modified to my tastes (extra float, siren, etc.)

 

[Eman79]

Or, for a fail safe option, get a pump stopper kit from Aquahub.com.

I'm more looking for a failsafe option to keep the water flowing. I have an aquarium controller, and I am considering setting the pump to shut off if the sump empties, but am more interested in preventing the problem in the first place.

Overflow SHOULDN'T (fingers crossed) be an issue as i set the water level in the sump and the overflow at a level that if pump fails, sump won't overflow, and if siphon fails, tank won't overflow.

 

[Ron Reefman]

I had 'U'tube siphons before and ended up installing a plastic nipple in the top of the 'U' and hooked in an Aqualifter pump. It worked fine. I even ended up putting it on a timer so it would only run 30 minutes every 4 hours just to keep the bubbles sucked out. It ran fine for 3 years until I switched tanks. And since my current tank was set up without emergency drains (my bad) I recently set up a CPR siphon overflow box with the Aqualifter and one of my drilled drains is an emergency drain. I like the CPR siphon box much better than the 'U'tube style.

 

[Eman79]

Hmm. I don't think I'm having an issue with air bubbles but I will check to see if there is any air in the U tube when I get home. Just checked out CPR's video. I agree that seems like an improvement over the U tube design. Do you notice it collecting much air?

As far as the aqua lifter is concerned, that seems like a good way to restore flow without sucking on a hose stuck in the u tube and I like how it can be automated. My only question is how you have it plumbed. Seems that you would have to have the outflow from the pump under water to keep from introducing air into the system when the pump is shut off. Then, of course it will siphon also, even without the pump running, right? (Not that I see how that would be an issue).

 

[sail33]

I've had the same problem. It started when I installed a second over flow box to provide flow to my algae turf scrubber. It happened because the box was not low enough in the display tank. The U tube was sucking a little air and kept going dry. I set it high in order to reduce flow to the ATS. Bad idea. I lowered the box to be even with the primary and the problem was solved.
No parts to buy, no extra work. not one bubble in the U tube.

 

[keithhays]

Hmm. I don't think I'm having an issue with air bubbles but I will check to see if there is any air in the U tube when I get home. Just checked out CPR's video. I agree that seems like an improvement over the U tube design. Do you notice it collecting much air?

As far as the aqua lifter is concerned, that seems like a good way to restore flow without sucking on a hose stuck in the u tube and I like how it can be automated. My only question is how you have it plumbed. Seems that you would have to have the outflow from the pump under water to keep from introducing air into the system when the pump is shut off. Then, of course it will siphon also, even without the pump running, right? (Not that I see how that would be an issue).

You are not pumping water into the U-tube, you are sucking water out of the top of it. The pump runs all the time and is connected to the top of the U-tube via a nipple you will have to put in place. You are either loosing flow because of air in the tube or the electricity is going off when you are not there and you are loosing your siphon altogether because of the way it is plumbed. You should have the u-tube in such a way that if your return pump stops there is enough water on either side of the u-tube to keep water in it.

I am curious; how to you manage to loose the siphon without a flood?

 

[Eman79]

I understand that you are sucking water and any air out of the top of the U tube. Just seems that having a small pump running 24/7 seems excessive. But I guess that goes 2 ways. 2 failures in a year up in running is both a low failure rate but also 2 failures too many. If its taking that long to build up enough water, I could probably just remove the water once a month. Maybe I should just keep a close eye on it for a while.

I don't lose suction when the power goes out... I turn off my return pump every day for feeding. So if its one or the other, then I guess I have air bubbles.

I don't overflow when I lose suction because I have a very small sump. It holds around 10 gallons but only has around 4 gallons in it when operating normally. Overflow is set an inch or so below the top of the glass, so when I lose suction, and the sump empties, the water level is at the top of the glass. My only overflow was the first time this happened when my wife didn't understand the problem and filled the sump with 5 gallons of ATO water. Doh!

 

[keithhays]

I understand that you are sucking water and any air out of the top of the U tube. Just seems that having a small pump running 24/7 seems excessive. But I guess that goes 2 ways. 2 failures in a year up in running is both a low failure rate but also 2 failures too many. If its taking that long to build up enough water, I could probably just remove the water once a month. Maybe I should just keep a close eye on it for a while.

I don't lose suction when the power goes out... I turn off my return pump every day for feeding. So if its one or the other, then I guess I have air bubbles.

I don't overflow when I lose suction because I have a very small sump. It holds around 10 gallons but only has around 4 gallons in it when operating normally. Overflow is set an inch or so below the top of the glass, so when I lose suction, and the sump empties, the water level is at the top of the glass. My only overflow was the first time this happened when my wife didn't understand the problem and filled the sump with 5 gallons of ATO water. Doh!

That's funny :lmao:. The little pumps don't pull that much electricity, it should be fine. I have to say even with the pump, you still run the same risk, but a lot less than without it.

 

[Saltydrip]

I run an eshops overflow with no failures for over a year now. I believe you might not have enough flow threw your overflow. If you have the proper amount of flow then the small amounts of air that find there way into the U-tube just get sucked right out.

What pump and overflow are you running??

 

[mr.maroonsalty]

Instead of the aqualifter, you can use the Venturi port on the small aquaclear style powerheads.

Just went through this with a person here last week, at least you know that you have a lifereef knockoff; that would tell me to look for design flaws. Do you lose syphon gradually, or all at once? If its gradually accumulating air, that means its not purging itself, which is the major design feature the u-tube has over the weir syphon; I would look at flow rate to be the problem if the syphon rate gradually slows. What pump are you using, and what size is you plumbing, how long is it, how many fittings are you using to get the water up to the tank?

Putting a pump on the syphon to keep the air purged could be helpful, but it will NOT prevent it from failing! Using a syphon drain requires monitoring. I am still using a CPR box on my old tank that has about two weeks left. It has slowed a good handful of times over the years 4-5, spilled slowly over the top a few times. There are a number of diferent reasons it will let air in, but the point is it will. With these boxes you don't have any back up, so you must do your best to regularly maintain them.

 

[Eman79]

at least you know that you have a lifereef knockoff; that would tell me to look for design flaws.

I would look at flow rate to be the problem if the syphon rate gradually slows. What pump are you using, and what size is you plumbing, how long is it, how many fittings are you using to get the water up to the tank?

QUOTE]

The system itself is OLD. (Tank date stamp is 1986) Ran in my friends SCUBA shop for years, followed by my parents house and I reserected it last year after about a decade in storage. That said, I doubt it is a design flaw as it never seemed to have issues before. That said, I DID have to replace the U-Tube and it is of a slightly different design, and it probably needs to be cleaned. That should probably be my step 1.

Recently (since the problems) upgraded from a mag7 on 1/2" plumbing to a Eheim Compact+3000 on 3/4" plumbing. I have it turned all the way down, as it seemed to be pumping faster than the overflow could handle at max. It has about 4' head height, 6' of flex tubing (3/4 as stated) down into 1/2 inch lockline J with 2 outflows and a check valve.