Airphotog
Love my Nikon
Anyone use these? If so how do you like it?
Continuous overflow boxes
- Thread starter Airphotog
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jaygalindo
Mariners Fanatic
if you maintain them and keep an eye on them then they work fine. It not very difficult to drill though...
Airphotog
Love my Nikon
Why would I drill it?
I think he's referring to drilling your tank, to avoid the need for an overflow box.
There are 2 major designs, in overflow boxes. U-tube and Non U-tube styles. Each have their own issues.
The U-tube styles are dependent on having the flow ratings of the box and return pump matched. If the pump is putting out too little flow, air bubbles will accumulate in the U-tubes. These air bubbles will reduce the flow, going through the U-tubes, eventually causing the loss of vacuum and failure of the U-tubes. Because of this, the U-tubes need to be watched, closely, and primed, when needed.
The non U-tube styles, such as CPR Overflow boxes, can run at any flow rating, up to their maximum, without issues, IF they are used correctly. They have a nipple, on top of them, that hooks to the venturi of a power head, OR an Aqualifter, via airline tubing. As long as the nipple and airline tubing doesn't become plugged, and as long as the power head or Aqualifter don't fail, these work very well. However, if, for any reason, water stops flowing through this airline tubing, these types of overflow boxes fail.
There are 2 major designs, in overflow boxes. U-tube and Non U-tube styles. Each have their own issues.
The U-tube styles are dependent on having the flow ratings of the box and return pump matched. If the pump is putting out too little flow, air bubbles will accumulate in the U-tubes. These air bubbles will reduce the flow, going through the U-tubes, eventually causing the loss of vacuum and failure of the U-tubes. Because of this, the U-tubes need to be watched, closely, and primed, when needed.
The non U-tube styles, such as CPR Overflow boxes, can run at any flow rating, up to their maximum, without issues, IF they are used correctly. They have a nipple, on top of them, that hooks to the venturi of a power head, OR an Aqualifter, via airline tubing. As long as the nipple and airline tubing doesn't become plugged, and as long as the power head or Aqualifter don't fail, these work very well. However, if, for any reason, water stops flowing through this airline tubing, these types of overflow boxes fail.
Xtremedave67
Well-known member
I have an overflow, my 1st time with a Fuge/sump.....Ill never do it again....Ill buy a drilled tank or drill my own.
once I hooked up an Aqualifter it became less painful but like said above got to keep an eye on things
once I hooked up an Aqualifter it became less painful but like said above got to keep an eye on things
jrgilles
Well-known member
I have 2 overflows. One running at a full syphon (virtually silent operation, controlled with a ball valve (although I wish it was a gate valve....)) and one that only has a trickle going through it which maintains water level and is there as a backup in case the main drain clogs.
They work great. The main drain overflow box never loses syphon or builds up air, the secondary drain gets a bit of air in it, so I remove it about once a month with a lift pump ($12) so the syphon doesn't break.
They work great. The main drain overflow box never loses syphon or builds up air, the secondary drain gets a bit of air in it, so I remove it about once a month with a lift pump ($12) so the syphon doesn't break.
Airphotog
Love my Nikon
I need to get an aqualifter.
Get 2, in case 1 fails. I've never had 1 fail, but it does happen and their inexpensive
Krish
RF STAFF
Agreed. I've had them fail on me. I always keep a spare on hand. Another option is using a powerhead in place of an aqualifter which you can place in your sump out of sight.
jrgilles
Well-known member
On my main drain, I don't even use an aqua lifter, and never had an issue. I do have a piece of airline tubing that hangs down from the overflow into the sump and drips, maybe a drop every 30 seconds or so, and that has kept it air free. I just tied the bottom end of the tubing in a knot, and it very slowly leaks into the sump.
The aqualifter is on my secondary drain that has almost no flow. I turn it on once a month for maybe 20 seconds, then shut it back off (have a 1/4" ball valve on the end of it so I can close it off)
The aqualifter is on my secondary drain that has almost no flow. I turn it on once a month for maybe 20 seconds, then shut it back off (have a 1/4" ball valve on the end of it so I can close it off)
Airphotog
Love my Nikon
I am thinking that a float switch might be in order. If lose siphon what keeps the pump from emtying the sump and overflowing the tank.
Krish
RF STAFF
My experience with the CPR overflows is if the aqualifter kicks the bucket, you won't lose siphon right away. For me it took a few hours for enough air to build up in there to stop the flow and it never actually got to that point for me for it to be a problem. Overflows that utilize a U siphon tube are the best at keeping a siphon. They never lose it's siphon ever. The only way would be if you pulled the U tube out. Also, they don't require any pumps. The downside to them though is they take up a bit more space in the tank compared to the CPR's. Here is an example of the type of overflows I am taking about. I'm sure you have seen them. You can see them in the top few rows in the link below
http://premiumaquatics.com/aquatic-supply/MLA.html
http://premiumaquatics.com/aquatic-supply/MLA.html
MrGone
:)
I ran two of them for a year and never had an issue, selling them now (CPR CS90 and CS102).
jrgilles
Well-known member
Yea, thats why I have 2 drains. One is backup. A float switch would also be awesome, or both even. Can't have to much redundancy when it comes to flood protection...
Airphotog
Love my Nikon
I agree. Water on the carpet would not be good.
fishoutofwater
Well-known member
i have a coast to coast over flow with 2 x 1.5" drains straight down to 2 sumps that are plumbed together. super quiet and very nice.
+2
3years now no issues..yet. I have tested power outages and adjusted things if needed. Maybe i am lucky but everytime i have tested or experienced the real thing i have never had an issue with it losing siphon or not being able to start its self back up. i will add the only maintenece i do to my aqua lifter is pull off the hose from the box and blow through the line and reconect it really fast.
let me say this though the next time i will have built in overflows or drilled tank hands down.
bens63imp
29 DT w/ 24 aquapod fuge
I myself have a simple U tube and I drilled a hole where the air bubble @ the very top would be and simply suck the air out via me lungs with a shut off valve. too much maintinance but works well. Never once yet a totall loss of vacume
Airphotog
Love my Nikon
I am getting a better feeling about using it now.
Ichthys
Well-known member
Siphon
There are only two ways for an overflow to fail. 1) it loses siphon, and 2) it gets blocked. Most people have issues with losing siphon and thats where you get all the fixes about aqualifters, and airline tubing, holes to bleed air, etc etc... I much prefer to prevent than to fix... If you position the inlet of your J tube properly in the intake strainer box, then it never gets air in it in the first place. Its all about the water flow rushing through the strainers teeth and falling into the water level in the strainer which is usually 1/2 to 1" below the DT water surface. This causes tiny bubbles to be driven down into the box which in turn get sucked up into the J Tube. It is a matter of sizing, return flow rate, size of overflow strainer in tank, tooth size and spacing, diameter of J Tube, all these work together to either create nice flow with few bubbles, or tumultuous flow with lots of bubbles.
There are only two ways for an overflow to fail. 1) it loses siphon, and 2) it gets blocked. Most people have issues with losing siphon and thats where you get all the fixes about aqualifters, and airline tubing, holes to bleed air, etc etc... I much prefer to prevent than to fix... If you position the inlet of your J tube properly in the intake strainer box, then it never gets air in it in the first place. Its all about the water flow rushing through the strainers teeth and falling into the water level in the strainer which is usually 1/2 to 1" below the DT water surface. This causes tiny bubbles to be driven down into the box which in turn get sucked up into the J Tube. It is a matter of sizing, return flow rate, size of overflow strainer in tank, tooth size and spacing, diameter of J Tube, all these work together to either create nice flow with few bubbles, or tumultuous flow with lots of bubbles.
