overflow box

klaxan · 09/15/2007, 10:59 AM

what is a good overflow box, I have been looking at one from aquatraders, would this be a good choice?

albert2k · 09/15/2007, 11:13 AM

one of the best an at good price in aquatraders. I bought the one of 1200G/H and works great.

DarG · 09/15/2007, 12:55 PM

Those are C siphon type boxes. You need to use a seperate pump like an Aqualifter or a power head with venturi intake to attach to the air nipple on the top of the overflow in order to continuously clear the air from the unit. Otherwise, air bubble will accumulate and you lose siphon. The reason is that the C-Siphon type overflows dont have enough water velocity through them to keep the bubbles clear. If the pump fails or something clogs the air nipple, the overflow loses siphon and fails and you end up overflowing the tank and very possibly flooding the room. Also, very near impossible to thoroughly clean inside the siphon area.
C-Siphons work great when they work but they are a bit risky to use because of their reliability on a special pump to keep them clear for air.

I would seriously consider a regular U-Tube type overflow. They dont require anything to actively clear the bubbles, the water velocity through the U-Tubes does that on it's own. The "best" are probably the Lifereef units. But they are expensive, over 100 bucks for a single and near 200 for a double.
There are others that are reliable and built well and cost less.
Just need to find a reputable one that wont lose siphon after the power goes out. I think that Hurricane makes one that is good, and less expensive. I think Amiralce has reliable ones as well, or atleast they used to. I even have a cheap ebay unit that wont lose siphon (it was about 40 bucks). There are several good ones. Just need to watch out for some of the super cheapies. There are still some crappy ones out there that wont keep siphon after power outage.

klaxan · 09/15/2007, 03:20 PM

I am looking for a double , $200 for a plastic box is hard to spend

DarG · 09/15/2007, 03:59 PM

Quote:

Originally posted by klaxan
I am looking for a double , $200 for a plastic box is hard to spend

Understandable. I did say there were others.
How about ...

http://store.hurricanefilters.com/quprov2.html

Eshopps is another company with an inexpensive double overflow available.

It'll cost you about 15 bucks more than the C-Siphon after add the Aqualifter pump to the C-siphon. IMO, 15 bucks is worth not having to worry about relying upon a dead or clogged pump. I think the Hurricane comes with the hoses too, not sure. I have owned both types.

Opinions on C-Siphon overflows in general are pretty low, it's not just me. Just giving you the info, that's all. Get some more input and opinions before you decide on the C-Siphon and best of luck with whatever you decide upon.

klaxan · 09/15/2007, 08:36 PM

thanks for helping find some other options

baldgeek · 09/15/2007, 10:32 PM

For a long time, I have used double U-tube overflows with little if any issues. Two things that I do are:
1) Use a PVC check valve so that if the power goes out, the water level in the tank does not drop making it less likely the siphon will break and
2) Drill a small hole in the top of the U-tube with a piece of rigid tubing siliconed in just a 1/4" inside the tube. I attached regular airline tubing to the other end with a stopper. If it loses siphon, it takes just a quick suck to get it going again without having to take the tube out of the box and run the tubing inside, then sucking in order to start it again. Has always worked really well and it much faster.
I should add that none of my tanks are drilled, so I am relegated to overflows on all of them.

baldgeek · 09/15/2007, 10:34 PM

I should have added that the check valve, as you might guess, is the first thing above the pump return. That is, threaded pvc, then check valve, then return plumbing to the tank.

ZachStep · 09/15/2007, 11:16 PM

How do these U-tube oveflows get started? Does anyone have a video on it? I have a cheap ebay C-siphon from a couple years ago (supposedly new), and I cant even figure out how to use it

flipteg · 09/15/2007, 11:20 PM

i have a Hurricane overflow that i bid and won on eBay for $41 shipping included... the only catch is, the included drain hose is only 3' which is about a foot and a half too short for what i need...

i left a rigid air hose in the tube to suck out the air... the other end is connected to an Aqualifter pump... the Aqualifter is helping with taking out the bubbles, but in the case that the Aqualifter fails, the syphon does not depend on the Aqualifter to maintain syphon... also, the Aqualifter can restart a lost syphone by itself... the overflow that i have is rated to overflow 600gph... i am running much less than that... probably only 100gph... with such a slow flow through, the U-tube does accumulate bubbles, but the Aqualifter sucks them completely right out... in the event that the Aqualifter fails, i would have atleast 2 or 3 days to notice the abnormally high bubble accumulation in the U-tube and do something about it... i think it's the best compromise on using a pump as an aid, but not depending on the pump to keep syphon...

sjm817 · 09/16/2007, 06:59 AM

A decent overflow properly setup does not need an Aqualifter since it should never collect any air in the U Tube. The siphon should never break and need to be restarted. If your U Tube is collecting bubbles, you likely need to increase the flow. That is the correct way to fix the issue and will be by far the most reliable. A hole drilled into the top with a pump turns a simple, reliable design into an unreliable C-Siphon type unit.

DarG · 09/16/2007, 08:58 AM

I agree. I have a lifereef. It will NOT fail, ever. But there are other, less expensive units just as relaible, maybe not as well built (overbuilt) but just as reliable.

You do have to start the initial siphon and I use an aqualifter and piece of airline tubing in the u-tube for that. But it is never left in place. I dont need it.

flipteg · 09/16/2007, 10:12 AM

Quote:

Originally posted by sjm817
A decent overflow properly setup does not need an Aqualifter since it should never collect any air in the U Tube. The siphon should never break and need to be restarted. If your U Tube is collecting bubbles, you likely need to increase the flow. That is the correct way to fix the issue and will be by far the most reliable. A hole drilled into the top with a pump turns a simple, reliable design into an unreliable C-Siphon type unit.

i agree, but some of us don't have the desire to run a 600gph flow rate through the refugium...

sjm817 · 09/16/2007, 10:47 AM

You dont need anywhere near 600 GPH. Typically, ~ 200 GPH with a 1.25" U Tube is enough to keep bubbles pushed through. Most HOB overflows cant even handle 600 GPH anyway and top out around 400 GPH despite the "ratings". If you want to run less than 200 GPH, use a smaller diameter U Tube.

09/15/2007, 10:59 AM	#1
klaxan Registered Member Join Date: May 2007 Location: Kansas Posts: 55	overflow box what is a good overflow box, I have been looking at one from aquatraders, would this be a good choice?

09/15/2007, 11:13 AM	#2
albert2k Registered Member Join Date: May 2002 Location: Puerto Rico Posts: 333	one of the best an at good price in aquatraders. I bought the one of 1200G/H and works great. __________________ Saludos desde la bella isla del encanto, Puerto Rico. Current Tank Info: 90 gal-wet/dry-refugium

09/16/2007, 06:59 AM	#11
sjm817 On Yer left! Join Date: Sep 2004 Location: Northern VA Posts: 18,777	A decent overflow properly setup does not need an Aqualifter since it should never collect any air in the U Tube. The siphon should never break and need to be restarted. If your U Tube is collecting bubbles, you likely need to increase the flow. That is the correct way to fix the issue and will be by far the most reliable. A hole drilled into the top with a pump turns a simple, reliable design into an unreliable C-Siphon type unit. __________________ - Scott

09/16/2007, 10:47 AM	#14
sjm817 On Yer left! Join Date: Sep 2004 Location: Northern VA Posts: 18,777	You dont need anywhere near 600 GPH. Typically, ~ 200 GPH with a 1.25" U Tube is enough to keep bubbles pushed through. Most HOB overflows cant even handle 600 GPH anyway and top out around 400 GPH despite the "ratings". If you want to run less than 200 GPH, use a smaller diameter U Tube. __________________ - Scott Last edited by sjm817; 09/16/2007 at 10:52 AM.

09/15/2007, 12:55 PM	#3
DarG Registered Member Join Date: Dec 2006 Posts: 5,515	Those are C siphon type boxes. You need to use a seperate pump like an Aqualifter or a power head with venturi intake to attach to the air nipple on the top of the overflow in order to continuously clear the air from the unit. Otherwise, air bubble will accumulate and you lose siphon. The reason is that the C-Siphon type overflows dont have enough water velocity through them to keep the bubbles clear. If the pump fails or something clogs the air nipple, the overflow loses siphon and fails and you end up overflowing the tank and very possibly flooding the room. Also, very near impossible to thoroughly clean inside the siphon area. C-Siphons work great when they work but they are a bit risky to use because of their reliability on a special pump to keep them clear for air. I would seriously consider a regular U-Tube type overflow. They dont require anything to actively clear the bubbles, the water velocity through the U-Tubes does that on it's own. The "best" are probably the Lifereef units. But they are expensive, over 100 bucks for a single and near 200 for a double. There are others that are reliable and built well and cost less. Just need to find a reputable one that wont lose siphon after the power goes out. I think that Hurricane makes one that is good, and less expensive. I think Amiralce has reliable ones as well, or atleast they used to. I even have a cheap ebay unit that wont lose siphon (it was about 40 bucks). There are several good ones. Just need to watch out for some of the super cheapies. There are still some crappy ones out there that wont keep siphon after power outage.

09/15/2007, 03:20 PM	#4
klaxan Registered Member Join Date: May 2007 Location: Kansas Posts: 55	I am looking for a double , $200 for a plastic box is hard to spend

09/15/2007, 08:36 PM	#6
klaxan Registered Member Join Date: May 2007 Location: Kansas Posts: 55	thanks for helping find some other options

09/15/2007, 10:32 PM	#7
baldgeek Registered Member Join Date: Jun 2005 Location: Austin, TX Posts: 94	For a long time, I have used double U-tube overflows with little if any issues. Two things that I do are: 1) Use a PVC check valve so that if the power goes out, the water level in the tank does not drop making it less likely the siphon will break and 2) Drill a small hole in the top of the U-tube with a piece of rigid tubing siliconed in just a 1/4" inside the tube. I attached regular airline tubing to the other end with a stopper. If it loses siphon, it takes just a quick suck to get it going again without having to take the tube out of the box and run the tubing inside, then sucking in order to start it again. Has always worked really well and it much faster. I should add that none of my tanks are drilled, so I am relegated to overflows on all of them.

09/15/2007, 10:34 PM	#8
baldgeek Registered Member Join Date: Jun 2005 Location: Austin, TX Posts: 94	I should have added that the check valve, as you might guess, is the first thing above the pump return. That is, threaded pvc, then check valve, then return plumbing to the tank.

09/15/2007, 11:16 PM	#9
ZachStep Registered Member Join Date: Dec 2006 Location: Central Indiana Posts: 50	How do these U-tube oveflows get started? Does anyone have a video on it? I have a cheap ebay C-siphon from a couple years ago (supposedly new), and I cant even figure out how to use it

09/15/2007, 11:20 PM	#10
flipteg Registered Member Join Date: Oct 2004 Posts: 910	i have a Hurricane overflow that i bid and won on eBay for $41 shipping included... the only catch is, the included drain hose is only 3' which is about a foot and a half too short for what i need... i left a rigid air hose in the tube to suck out the air... the other end is connected to an Aqualifter pump... the Aqualifter is helping with taking out the bubbles, but in the case that the Aqualifter fails, the syphon does not depend on the Aqualifter to maintain syphon... also, the Aqualifter can restart a lost syphone by itself... the overflow that i have is rated to overflow 600gph... i am running much less than that... probably only 100gph... with such a slow flow through, the U-tube does accumulate bubbles, but the Aqualifter sucks them completely right out... in the event that the Aqualifter fails, i would have atleast 2 or 3 days to notice the abnormally high bubble accumulation in the U-tube and do something about it... i think it's the best compromise on using a pump as an aid, but not depending on the pump to keep syphon...

09/16/2007, 08:58 AM	#12
DarG Registered Member Join Date: Dec 2006 Posts: 5,515	I agree. I have a lifereef. It will NOT fail, ever. But there are other, less expensive units just as relaible, maybe not as well built (overbuilt) but just as reliable. You do have to start the initial siphon and I use an aqualifter and piece of airline tubing in the u-tube for that. But it is never left in place. I dont need it.