pvc overflow for others to share

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try this one

overflow.gif


yes it works there is a thread in the newbie forum yes I know I am a newb also
 
only problem i see is when power shuts off, it'll take a bit long for it to start syphoning again. is it also loud?
 
i'd have a very hard time trusting the check valve long term. it's just there to start it, right? or is it to hook to an aqualifter for constant bubble removal? i'd use a microballvalve instead if the former, and i'd pick another design if the latter and it requires constant bubble removal because the aqualifter will eventually fail.
 
This design does not lose siphon. The "U"s both in an out of the tank keep the bridge pipe full of water up and over the side of the tank. When the water flow restarts it just starts working again.
 
just looking at it again, try turning it off for say 30 mins... then turn it back on, what's going to happen is you see where it goes down to the sump and pipe-a next to it, pipe-a's water level is going to go down to the same volume as the T on the sump side. the concept is good though, similar to the CPR overflow boxes right? so does it push too much water out while the aqualifter is on when it first starts up?
 
How loud is the sucking noise that is created...i have a similar diy pvc overflow concoction and i have a hole to break syphon once the water level gets low and it seems to scream once it gets low
 
it should not take anything to restart, since it shouldn't lose siphon to begin with.

overflow.jpg


water will drain down to the red line, leaving the blue smudged pipe still full of water.

i've never run one, but my guess is it will be as quiet as they come. it will take a bit of head pressure to move water from one side to the other fast enough and with it dipping that low into the tank, it shouldn't suck air really.
 
They syphon restarts immediately. I've had it off overnight and it started right back up the next day. Its slightly loud, but with a cap on the vent stack and a small hole, its almost silent. I'm still playing with the hole size to get it right, but mine is a QT tank so functionality is more important.

The check valve is just to suck out/release any air that might accumulate in that area.
 
Like all siphon type overflows, you are at the complete mercy of that airline checkvalve. If it leaks even a tiny bit while the pump is off, your siphon is gone and you're flooded when the pump restarts. Keep an eye on that little bugger :)
 
<a href=showthread.php?s=&postid=7844312#post7844312 target=_blank>Originally posted</a> by H20ENG
Like all siphon type overflows, you are at the complete mercy of that airline checkvalve. If it leaks even a tiny bit while the pump is off, your siphon is gone and you're flooded when the pump restarts. Keep an eye on that little bugger :)
Not true. A traditional U Tube siphon overflow has no airline or check valve. There is no place for air to leak and break siphon..
 
OK, Like all siphon type overflows that use a checkvalve for air removal....:rolleyes:

And then there are the siphons that get bubble acumulation in the top of the tube...

All I'm saying is to keep an eye on them. Like the rest of the equipment, a little maintenance will save you from a LOT of heartache.
 
<a href=showthread.php?s=&postid=7844388#post7844388 target=_blank>Originally posted</a> by H20ENG
OK, Like all siphon type overflows that use a checkvalve for air removal....:rolleyes:
That would be the poorly designed CPR and similar
And then there are the siphons that get bubble accumulation in the top of the tube...
A decent properly setup U Tube overflow should never accumulate a single bubble...ever. It will run indefinitely without issue.
All I'm saying is to keep an eye on them. Like the rest of the equipment, a little maintenance will save you from a LOT of heartache. [/B]
And get a decent overflow o begin with. If it needs a pump to remove air accumulation, look elsewhere.
 
http://reefcentral.com/forums/showthread.php?s=&postid=7844140#post7844140

Never accumulate a single bubble, lol? Are you serious? Even during power outages.... Really I can not imagine an u tube that couldn't get a single air bubble ever. I don't see how this is not a decent overflow. I like the one I built better, but still don't see a major problem with it this one.

I built mine, tested it for weeks, and left it turning itself on and off certain times of the days for months in a locked room in a house no one was hardly in. Not a single problem. Don't nock it unless you've tried it.
 
I do not like that second photo graph you posted though. Looks like your water is rising in the tank a bit to fast for it to keep up with. A little snail popping in the top and slowing it down a little bit could be big trouble. I would slow the pump a little or add a second return. (or build one with larger tubing, but I wouldn't go that far) When myn ran the water level never got more then a mm above my overflow pipes.
 
<a href=showthread.php?s=&postid=7844473#post7844473 target=_blank>Originally posted</a> by Gordonious
http://reefcentral.com/forums/showthread.php?s=&postid=7844140#post7844140

Never accumulate a single bubble, lol? Are you serious? Even during power outages.... Really I can not imagine an u tube that couldn't get a single air bubble ever. I don't see how this is not a decent overflow. I like the one I built better, but still don't see a major problem with it this one.

I built mine, tested it for weeks, and left it turning itself on and off certain times of the days for months in a locked room in a house no one was hardly in. Not a single problem. Don't nock it unless you've tried it.
Yes, I'm serious. None, never. If you accumulate air, something is wrong. I've been running 2 years without ever having air accumulation. Let me clarify. When the return pump is off, a little air may sit at the top of the U Tube. Once you start the pump all of it is pushed through from the water flow. When running, no air should ever accumulate. None.

BTW, I'm posting about a traditional U Tube overflow, not the PVC one. I have no experience with these overflows and dont have an opinion on them. I would say that I personally would want a larger weir area for surface skimming than an open PVC pipe.
 
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I understand what your posting about that's why I said, don't knock it till you try it, lol. Two questions: Do you run on a battery back up? Secondly has never never been enough air slip in to stop it? The lab I worked at had one system that actually used a traditional overflow. I came in one day and the tank was cloudy, I looked in the back and water was going through the U-tube, but a massive bubble was stuck in there due to a power outage the night before.

How I see it either design could get bubbles in it. If you use an aqualifter to pull the bubbles out then it would be a problem for neither design. By that logic the PVC is a lot safer.

When the power goes out, not blinks goes out, on a traditional U-tube it can stop siphoning and/or have a large amount of air in it after 30 seconds. The elaborate PVC like the one I built pulled and pulled. I was still trying to pull water and air through it after 5 minutes of the power being out. Even if the power was out for say 20 days, I tired this, once the pump was running again so was the overflow.

I was really unsure of this when I first started looking at it as well. If you want to come over sometime I'll hand you an air pump and show you were the plug is to my main pump. You'll be surprised.

Don't be scared of something new till you've tested it, lol. ;-)
 
I'm very skeptical of every PVC siphon I've ever seen. Every place a pipe butts into a fitting there's an expansion that can act like a venturi and create (not just trap) an air bubble.

Dan
 
<a href=showthread.php?s=&postid=7844699#post7844699 target=_blank>Originally posted</a> by Gordonious
Do you run on a battery back up?
No
Secondly has never never been enough air slip in to stop it?
No. It has been off for days and starts back up every time. I power off every day for 10 min during feeding as well.
The lab I worked at had one system that actually used a traditional overflow. I came in one day and the tank was cloudy, I looked in the back and water was going through the U-tube, but a massive bubble was stuck in there due to a power outage the night before.
Poor overflow or not enough flow

How I see it either design could get bubbles in it. If you use an aqualifter to pull the bubbles out then it would be a problem for neither design. By that logic the PVC is a lot safer.
As above, you should never get air. If you do, something is not right.

When the power goes out, not blinks goes out, on a traditional U-tube it can stop siphoning and/or have a large amount of air in it after 30 seconds.
Maybe an improperly setup or very poorly designed one. Otherwise, not true.

Don't be scared of something new till you've tested it, lol. ;-) [/B]
I will never use an overflow again that needs a pump to pull out air. I learned my lesson running a CPR. I'll use one that doesn't accumulate air and doesn't need an external pump to function. many people including myself have run for many years with a normal U Tube overflow without the slightest issue. Lifereef advertises no reported failures in the 18 years they have been selling them. I have a friend that has some no name generic U Tube overflow that has been running problem free for 7 years. He loses power a lot during the Winter months.
 
Ok, lets say I'm trying to learn here. For your first four comments.: How is it poor? Please explain. If they got air in the lab, what was not set up/designed right?

The design I used did not require the pump to function, it just helped, and why would it be a huge problem if it did require it? If your that worried about your electric bill what type of lights are you running?
 
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