Looking for Good DIY Hang On Overflow

[maginter]

Hi All -

I need a good DIY for a hang on over flow to support a 55 gallon tank. I would like to have somthing that can support as much as 900 gph. I have a 20 gallon sump, the 55 gallon is not RR and cant be drilled.

All help is appreciated.

Mark

[danferd2002]

http://www.melevsreef.com/acrylics/overflow.html

[Jester75]

Try Melev's (http://www.melevsreef.com) , he has some awesome plans there!

[Jester75]

Lol
:rollface:

[danferd2002]

lol jynx

[sjm817]

I would not build a CPR clone.

[maginter]

<a href=showthread.php?s=&postid=8477112#post8477112 target=_blank>Originally posted</a> by sjm817
I would not build a CPR clone.

And a CPR is????

[maginter]

<a href=showthread.php?s=&postid=8477030#post8477030 target=_blank>Originally posted</a> by danferd2002
http://www.melevsreef.com/acrylics/overflow.html

Thanks...This will help a lot

[RandyStacyE]

I’ve never attempted working with acrylic so I made an overflow out of PVC/ABS:
http://randystacye.com/diy_overflow.htm

If I were ever to make an acrylic overflow I would copy this one:
http://www.aquaticeco.com/index.cfm/fuseaction/product.detail/iid/4982
http://www.aquaticeco.com//images/items/675128_rgb.jpg

If you were to make or use a similar overflow I would definitely use a Durso Standpipe with it.

[maginter]

<a href=showthread.php?s=&postid=8477665#post8477665 target=_blank>Originally posted</a> by RandyStacyE
I’ve never attempted working with acrylic so I made an overflow out of PVC/ABS:
http://randystacye.com/diy_overflow.htm

If I were ever to make an acrylic overflow I would copy this one:
http://www.aquaticeco.com/index.cfm/fuseaction/product.detail/iid/4982
http://www.aquaticeco.com//images/items/675128_rgb.jpg

If you were to make or use a similar overflow I would definitely use a Durso Standpipe with it.

The PCV one is a pretty cool idea....Thanks

[sjm817]

<a href=showthread.php?s=&postid=8477502#post8477502 target=_blank>Originally posted</a> by maginter
And a CPR is????
A very unreliable design that does not use a U Tube. It uses an integrated C channel. Air accumulates and you need an air fitting and a vacuum pump to constantly pull out the air. A U Tube overflow does not have this problem.

[maginter]

<a href=showthread.php?s=&postid=8477830#post8477830 target=_blank>Originally posted</a> by sjm817
A very unreliable design that does not use a U Tube. It uses an integrated C channel. Air accumulates and you need an air fitting and a vacuum pump to constantly pull out the air. A U Tube overflow does not have this problem.

Thanks

[jeffgp]

i have the 1400 gph over flow from aquatraders and just hook up a power head to the air line to suck out the air bubbles . it works for me

[maginter]

I am just looking for a short term fix to use a sump until we get a 180 up and running. Something low cost and effective.

All the input has been great!

[D Ro Supafly]

<a href=showthread.php?s=&postid=8477830#post8477830 target=_blank>Originally posted</a> by sjm817
A very unreliable design that does not use a U Tube. It uses an integrated C channel. Air accumulates and you need an air fitting and a vacuum pump to constantly pull out the air. A U Tube overflow does not have this problem.

This is pretty easy to work around without a vacuum pump.

Attach the airline to one of the outputs from a gang valve and attach another piece of tubing to the input for the gang valve. Start the siphon by sucking air through the line attached to the gang valve input. Once you've got the siphon started, close the valve on the output.

The tiny air pocket left in the overflow will never grow unless the siphon is broken by either moving the overflow box (draining the water) or opening the valve.

[Reefbox]

I've built, operated and experimented with many Overflow boxes throughout the years and this design is what I've found to be the most reliable and best permormer out of any that I've experimented with.

http://i72.photobucket.com/albums/i196/reefpets/overflowbox.jpg

[sjm817]

<a href=showthread.php?s=&postid=8478777#post8478777 target=_blank>Originally posted</a> by D Ro Supafly
This is pretty easy to work around without a vacuum pump.

Attach the airline to one of the outputs from a gang valve and attach another piece of tubing to the input for the gang valve. Start the siphon by sucking air through the line attached to the gang valve input. Once you've got the siphon started, close the valve on the output.

The tiny air pocket left in the overflow will never grow unless the siphon is broken by either moving the overflow box (draining the water) or opening the valve.
The C channel overflows need the vacuum running all of the time, not just to start it. They will build up air from the water moving over the weir until there is enough to break the siphon. Then you have a big problem. A U Tube overflow has faster velocity and the bubbles are carried right through. No airline/vaccum needed.

[D Ro Supafly]

Have you ever tried it? Do you have direct experience with what I've described?

I have direct experience and it works.

My overflow pulls roughly 1200 GPH using this setup without accumulating air bubbles or losing the siphon.

Give it a try.

[sjm817]

No. Never tried a gang valve. How does it work? Maybe I misunderstood your post. Does it have a constant suction of some sort to constantly pull out the air accumulation?

My point is an overflow that needs external help such as a vacuum pump or other method of air evacuation is not a reliable design.

[D Ro Supafly]

It works because it eliminates the leak that most people have when they "pinch off" the siphon line (as the directions tell them to do in order to close the line). It doesn't need a constant source of evacuation once the siphon is started, it just needs to stay air tight.

[brackishdude]

I think the knock on CPR (no personal experience) is not that the opening at the top of the C-channel (to evacuate air and start the siphon) is leaky, but rather that flow of water over the "C" is at a low enough rate to allow air within the overflow water to reaccumulate at the top. If enough does, the siphon is broken.


The manufacturer, I believe, actually recognizeds this flaw and recommends that the opening be attached full-time to a venturi to constantly evacuate any accumulating air. Thos of us with powerheads know they are far from foolproof.

[D Ro Supafly]

They also recommend the "Tom Aqualift" vacuum pump for it. I have that brand overflow on one of my tanks. Instead of wasting a good ten dollar dosing pump, though (I'm being facetious about it... kind of...), I slapped silicone around the fitting and close the line with the gang valve. "Me no leaky"

[sjm817]

<a href=showthread.php?s=&postid=8479698#post8479698 target=_blank>Originally posted</a> by D Ro Supafly
It works because it eliminates the leak that most people have when they "pinch off" the siphon line (as the directions tell them to do in order to close the line). It doesn't need a constant source of evacuation once the siphon is started, it just needs to stay air tight.
All overflows, internal, HOB or otherwise create air bubbles from the water moving over the weir. Where do they go? How do you keep them from accumulating? If you have an overflow that carries no air from the water movement, you have a very, very unique situation.

My CPR air nipple clogged twice in 3 months which rendered the Aqualifter useless. It took less than 24 Hr for enough air (from the water falling into the weir) to accumulate to where it caused a failure.

[D Ro Supafly]

And this has what to do with tea futures in Taiwan? :)

Creating air bubbles is fine as the bubbles flow with the current. If your siphon is air tight, you won't accumulate the bubbles.

This is one of those cases where I wish we lived close by each other so I could show you.

Before I forget, let me also say I am not knocking U tube overflows. I have one that I am going to put on one of my refugiums. I'm just satinmg that the C style can be made bulletproof by making the siphon air tight.

[sjm817]

It has everything to do with the discussion.
The bubbles created by the water flowing into the overflow collect at the top of a CPR overflow. This is why they REQUIRE a vacuum pump to remove them. If your CPR will flow the bubbles through the C Channel, you are incredibly fortunate, because they normally dont work that way. I've never seen or heard of one except for yours that will do that.

Without a vacuum pump, they will typically fail from air accumulation in 24- 48 hrs.

What exactly is your setup? What model overflow? How much flow are you putting through it? Maybe you stumbled on a setup that could be duplicated. I did notice on mine, low flow created less bubbles going through the weir, less accumulation, but it was always present.

[DHyslop]

<a href=showthread.php?s=&postid=8480084#post8480084 target=_blank>Originally posted</a> by D Ro Supafly

Before I forget, let me also say I am not knocking U tube overflows. I have one that I am going to put on one of my refugiums. I'm just satinmg that the C style can be made bulletproof by making the siphon air tight.

You'd have to pay me an awful lot of money to get me to put one on my system!

Bubbles get in there no matter what. Bubbles will even form in there if they have the opportunity. You need a certain water velocity (regardless of flow rate in g/h) to reliably keep those bubbles moving.

A C-type siphon by its very nature has a slower water velocity for any given flow rate. A c-tube just isn't the right tool for the job and it makes me wonder who on Earth suggested making one for an aquarium to begin with. Really, as easy as it is to drill a tank no one should depend on any siphon.

Dan

[D Ro Supafly]

<a href=showthread.php?s=&postid=8480126#post8480126 target=_blank>Originally posted</a> by sjm817
It has everything to do with the discussion.
The bubbles created by the water flowing into the overflow collect at the top of a CPR overflow. This is why they REQUIRE a vacuum pump to remove them. If your CPR will flow the bubbles through the C Channel, you are incredibly fortunate, because they normally dont work that way. I've never seen or heard of one except for yours that will do that.

Without a vacuum pump, they will typically fail from air accumulation in 24- 48 hrs.

What exactly is your setup? What model overflow? How much flow are you putting through it? Maybe you stumbled on a setup that could be duplicated. I did notice on mine, low flow created less bubbles going through the weir, less accumulation, but it was always present.

I have 3 different CPR models on various tanks. At my office, I use CS100s on a 75 gallon and on a 45 bowfront. These never run for more than 6 months or so without me moving the tanks, it seems like. I set up the sumps the same way as my 180, though.

At home, on the 180, I use a CS202. I am not the original owner of the tank, but I set it up 5 years ago for a friend and coworker and did all the equipment work on it. i recently bought it from him because it had been in decline since Hurricane Wilma last year and he didn't have time to take care of it due to family concerns. I knew the tank like the back of my hand, so it was an easy choice to get it.

Right now, it's been three weeks since I broke the siphon because I needed to move the box from the side to the back to accomodate my new canopy. Prior to that, it ran for three weeks after a complete tank move. Prior to that, it ran for a little over three years without the siphon breaking. It was in a difficult spot to reach (a hole cut in a wall, between the living room and an aquarium closet, with metal shelves in the closet). The first time we ran it, using a wet dry instead of the current 40 gallon breeder for a sump, it ran for just a hair over two years (January 2001 until Valentine's 03, when he got the new sump as a present form his wife lol).

The only unusual part of the sump setup is the hoses. I use longer hoses than most people, so that the hose goes to the floor, curves up, and then goes over the sump to connect to plumbing on the top.

There is always an air pocket in each of the two overflow hoses, varying between 2 and 6 inches. The water flowing through the hose acts as if it is "filling up" the hose, closes the air bubble and then slowly goes down to it's maximum size again, then rushes to fill back up.

These air pockets are where all of the noise in the overflow come from. I occasionally adjust the "tubes" in each overflow bulkhead to quiet it down.

I don't think the length of the hoses has anything to do with the actual overflow, however. The original printout with instructions said to "pinch" the siphon tube closed. The instructions on the CPR site now say to use an aqualifter pump, a powerhead venturi, a check valve, or a gravity siphon. All of that is fine, but what works on the CPRs that I use is to put silicon around the air nipple, suck all the air out of the line, close the check valve, and spit the saltwater our of your mouth.

I guess I'm going to need to borrow a camera and take pics of this guy LOL

One thing I noticed is that I should probably replace the gang valve soon. It wasn't that corroded when i moved the tank here but now it's looking cruddy. It may be because I hung it on the side of the overflow instead of tossing it on top of the canopy. The old canopy was shorter and I didn't cut new lines because all I had was clear tubing and I prefer silicone for this. It is defginately cruddy now and if it corrodes out, I'll have leaks.

Also, Dan? I'm not brave enough to drill glass in a tank full of animals and possibly crack the glass when i have a reliable siphon. All of the local guys who have drilled tanks always say "I'll be glad to help but I'm not responsible if it cracks." That gives me the willies pretty bad.

[Jester75]

I guess everyone has had thier own experiences with different products but IME, I have never had a problem with my CPR cloned overflow. I built mine based on Melev's about 8 months ago and it has only lost siphon one time and that was when I was out of town and let the sump level drop to almost nothing. I have nothing continuously siphoning air out of it either. I just tried to make sure mine had a minimum amount of leaks. I too run my hose out to a gang valve and suck the air out to get it started, then shut the gang valve.

I am not saying they are perfect, just my experience with them. I have never used any type of U-tube siphon so I cant say how well they work or not.

[DHyslop]

<a href=showthread.php?s=&postid=8480707#post8480707 target=_blank>Originally posted</a> by D Ro Supafly
Also, Dan? I'm not brave enough to drill glass in a tank full of animals and possibly crack the glass when i have a reliable siphon. All of the local guys who have drilled tanks always say "I'll be glad to help but I'm not responsible if it cracks." That gives me the willies pretty bad.

Because it takes such a herculean effort to take everything out and put it in a rubbermaid first. Oh boy, how will I ever get that hour of my life back :)

A HOB overflow (any HOB equipment, really) is a kludge. Its not really good at anything: poor surface skimming length, poor reliability, generally poor construction.

Once you drill your tank and put in your own overflow the world looks a little different--its a bit more serious. Your overflow is better, more robust and more professional in every way and you'd never contemplate going back to the plastic toy that used to do its job.

Dan