diy overflow
 

so i found this diy overflow system online and wanting some feed back. if you have used it or know anything about it please let me know.
also i need to know what size pvc to use.
i have a 96g tank and thinking of running a 30g sump.

Yes it works, I did one a few years back. Setup two of the pipes systems in one box and used 3/4". The tank was a 90 gallon and I believe the return rate was about 600gph. I also used clear pvc pipe so you could see if bubbles were building up.

HTH

Thanks
 

Thanks for the feedback. Helps to know someone has used it with good results. Where did you find clear PVC? My local home depot looks like the only carry white and black. What size sump were you running?

where did you find the pic?

I found it via google just look up diy PVC overflow and you will find the link to go along with the pic.

I get 720,000 options when do that, I will be dead before I find it, could you possibly narrow it down before I die:)

I've been considering using a PVC overflow for one of my tanks, from the reading I've done, some people swear by them, some swear at them.

So far, what I've read suggests using inch and a quarter pipe to build the overflow with a fast enough flow rate to sweep small bubbles out of the pipe.

Some people also use an aqualifter pump attached to the pipe going over the edge of the tank to pull out any trapped air.

No first hand experience yet, but I plan to be building/testing one in the coming weeks.

I'll try but I don't think I saved the link. I found it via google. I'll see if I can find the page in my history but there's a good chance I won't find it lol.

Help
 

Ok so I built my overflow but it doesn't keep the water flowing anyone have any ideas why? It is based on the pictured i posted at the begining ofthis thread. I someone could help me out that would be fantastic thanks.

I have seen one once, I'll look around and find out what I can.


Took a look here is a link:

http://forums.saltwaterfish.com/vb/s....php?p=2401854
http://forums.saltwaterfish.com/vb/s...d.php?t=288154
http://www.aquaticplantcentral.com/f...ge-system.html
http://www.angelfire.com/ab/rayjay/DIYoverflow.html
http://www.youtube.com/watch?v=kjSLP...eature=related

Willpost more if I like them.
Bill

Do you have a pic of what you built, it would be easier to troubleshoot.

good article found by another refer its posted not that long ago here http://www.aquaticplantcentral.com/f...ge-system.html

http://farm3.static.flickr.com/2530/...f005dab5_o.jpg

this will not work the way it is you need a hole where it goes over the tank also a check velve there. this design is poor will work with a couple changes. check out the links above thay have a design that works realy well.

Bill

best guess i could make would be that the air hole is too small. As stated it would be great if you can post a pic of the one you made.

Did you Prime it properly?

i have two overflows ..one with the air flow....one without
I like the one without the best....never had any problems...just use a pump that is rated a little higher

heres a pic
 

here are a couple pics of what i built.
for who ever asked if i primed it properly yes i did i filled all the chambers with water. anyways if you can help that would be great thanks everyone..

How are you going to start the siphon on that?

Looks good tho, interested to see how it works

I think you would need a 1" or 1.5" drain line to make something like this work properly. Yours appears to be 1/2" pipe, thus incapable of draining a significant amount of water. You may also need a gate valve rather than a ball valve for more accurate control.

Something like that should really be built out of clear pipe so you can monitor the accumulation of air bubbles see if it is primed properly. If you are on a budget, you could get away with having just one clear PVC pipe and the rest white.

the cap on the pipe that goes up comes off nothing is glued together yet.
and its 3/4" pipe not 1/2". and that ball valve was the only one i could find at the hardware store so thats what i went with. so ya i just dont understand why i get the syphon going and then it just stops..

here is a pic i put in my paint program

As Sphelps mentioned, he used two 3/4" drains similar to yours to drain about 600 GPH. How much do you intend to run through yours?

While I don't think it's a good way to drain a tank, I've seen all kinds of variations of what you are doing, so let's go ahead and trouble shoot it so you can decide if it works for your application.

1) Attach a hose to the intake in the tank and run water through your drain for a minute to assure that all of the air is purged out of the pipes.
2) Run it with a modest pump (500 GPH) and let us know what happens.
- does the tank water level rise over the intake/overflow the tank?
- does the drain quickly siphon for a minute or two and shut down?
- does the drain make a toilet flush sound?
3) Play around with the valve, starting with almost completely closed and slowly work it open until you lose siphon.
4) Play around with the return pump and slowly increase the pressure/volume until the siphon can't keep up.
5) After you get it "tuned" to operate properly, do a simulated power outage and make sure it starts up on its own.

Are you using this with an overflow box for surface skimming? If not, you aren't getting efficient skimming and you will need a strainer to keep critters out.

Do you have a fail safe system if a snail clogs the pipe? Where does all that water in your sump go in the event of pump/power failure or pipe blockage?

Sometimes a cheap overflow ain't so cheap :)

I would say that the length of your pipe is too long after the siphon. the velocity of the water shooting down there is going to put alot of pressure on your intake, and with un-sealed joints, may be pulling in air. +1 to closing your valve 90% and trying again with a slower column of water in the pipe. Once you seal it up, you should be able to crank it open more.

Does the line in the tank suck any air at all?? If it gets any accumulated air in the over the top piece, it will loose siphon

did you prime by pouring? or prime by suction?

Ok well I don't want to run a pump for my overflow.
The pipe going down to my sump needs to be that long or it won't reach.
I primed it by filleing it with water and with suction niether worked.
It doesn't make any sense every other overflow I've seen on you tube works mint and for some reason mying won't. I'm just so confused this is my first overflow and I did it because I heard it was easy. Which it's not turnin out to be that way. Lol.

Can you get a siphon started at all? If you can, and it fizzles out after a bit, then chances are it's sucking air somewhere in the siphon loop. Either from the tank inlet, or the pipe connections. If the vent hole is not large enough, it may pull so hard it pulls a vortex in the tank end and sucks air that way?

i think it might be getting some air from the connections cause its not glued yet. but i finally got it to flow some water. i'm going to post a video on you tude and add the link to this page then everyone can see my issue. should have it up in the next ten mins or so stay tuned.

you tube
 

ok here is the link to my you tube video.

www.youtube.com/watch?v=hHeLRBUxwZc

Your vent hole is not large enouggh, Steve. The water level should only go down to the level of the pipe that your vent hole is in, Should never uncover the inlet like that. If the inlet sucks air, you will loose the siphon like how you are. keep increasing the vent hole bit by bit untill you find the diameter that works well.

It's hard to tell, but do you even have a vent just before the last 90 and the down pipe.

umm ok i'm kinda confuzed on what you mean by vent hole.. lol

OK, refer back to the pic posted earlier in this thread.

http://farm3.static.flickr.com/2530/...f005dab5_o.jpg

See the vent hole shown? this is for a siphon break. It lets air in and when the level of the tank drops below this, it lets more air in, causing the siphon i the downpipe to be lost BUT it keeps the water in the overflow pipe over the side of the tank, so when tank level rises above this vent hole level, the drain will automatically start

Without it, the overflow will completely drain the tank to the intake level, where it sucks in air, just like your Youtube vid does. Start with a 1/8" diameter hole and see how it works, if still same, try 3/16" What some people do is put a piece of airline in there and a John Guest valve, and can vary the valve depending on drain requirements. But fiddlin with drillbit holes will work good too

ok here is another picture to see if i understand what your saying.

Can't read anything on the pic, to small, but the sideways T that goes into the 90 that does on the downpipe to the sump. Between the T and the 90, drill a hole on the top of the pipe. 1/8" to start. this is a siphon break. I have never made a overflow like you have there, but I know you need an air inlet. Acctually, looking at that Drill the hole in the cap that you filled the pipe up with.


Try it first Without the cap on the top of the T, I bet it just may work fine without that cap, Fill it up, and then open valve and see

Ok I will try with out the cap and see what happens and then go from there. Thanks so much for all the help.

No problem, I know it may sound strange, drilling a hole in somehting that's draining water, but sometimes they drain water TOO well LOL. need some air to slow them down and equalioze things :D

Let us know how it works. It may be noisy with no cap, so thats why you vary the size of a hole in it, to allow just enough air, but not get that toilet sucking noise

I suspect you are not priming at all, I don't care how you force water in the bubbles have the capacity to remain in the top of the U, drill and tap and install a john guest fitting in the first u tube, fill as normal then draw the remaining air out of the top of the U then submerse the JG tube below the surface of the water and you should be good to go, the principle on this system is sound.

ok well i tried with out the cap and nothing drained out at all.
and yes i am priming it,im puting the garden hose in the pipe. check out the video i posted. i also moved the t joint down so it was lower than the water intake and that did nothing.
do you think it might be because the pipe isnt glued together? and its drawing in air at each fitting? there are just so many variables unvolved in this lol and ive never made one before so i dont know how to trouble shot the problem..

Ya Paul, your right, with a vent hole, it may need a fill hole at the "over the tank" section. When he filled it in the video, with no hole, it got a full suction, and because there was no vent to break suction when tank got to level, it continued to siphon untill the inlet got uncovered and broke the siphon that way.

Steve, it may not start with the cap removed like I suggested because there will not be water in the over the tank bend to start with. This needs to be full and no air in it in order to create the siphon from the tank. Then, the air inlet at the T, that makes it so the siphon will stop, when tank reaches that level, but the over the tank pipe remains full of water

I hope I'm not confusing you, I can see it clearly in my head but seeing and describing are 2 different animals LOL

OK, With my awesome paint skills, I revised a couple changes.

And ya it won't start without the cap. If you filled it, put cap on, started siphon, let run a little to ensure all air out of the over the tank pipe, then pull cap off I bet it may work.