CPR Overflow Boxes

[Pit Bull]

I was thinking of purchasing a CPR siphon ovrflw box ad was wondering what your experinces were with them. TIA

 

[CAPT PETE]

I wouldn't recommend getting the CPR overflow. I had the CS 102 and it required a lot of maintenance to keep it from clogging. You will also need a powerhead to get it to start after a power failure. If the powerhead doesn't restart, you'll have a major flood. I got rid of mine and bought a lifereef overflow. No problems and the only maintenance you have is to clean the overflow tubes when they get dirty. Do youself a favor and get a lifereef.

 

[fishfarmer]

Have you thought about getting your tank drilled? It should cost you about the same if not CHEAPER than a CPR with pump and tubing and the added insurance when it fails. I haven't used a lifereef, but heard they are better than CPR's which I do have sitting in a box :roll: .

 

[TommyBoy]

I have ran a cpr cs-100 for 3 yrs. with no single problem. if you set them up like they are designed to run they work great.Period.

 

[liquid]

That is until the powerhead dies and air gets sucked into the overflow which eventually stops the siphon and your tank overflows. I've had a friend that has had a CPR 90 (?) or higher on his 125 and about 1x per year it craps out on him overflowing his tank and it seems to happen every time he's on vacation.

If it were me, I'd look into getting your tank drilled if that's an option for you.

Shane

 

[newkie]

The problem with CPRs is that the siphon is spread out over the length of the overflow. This means water moves at a slower velocity allowing bubbles to build up breaking the siphon. CPR compensates for this design flaw by suggesting a venturi powerhead be connected to it to remove bubbles. Of course this is failure-prone. If correctly paired with a return pump you will lessen your chances for failure. You may not have a problem for years, but you're inviting disaster. U-tubes are superior in their design partly due to their simplicity. The water flows at a higher velocity through a u-tube so the bubbles carry through and do not collect. J-tubes move at even a higher velocity. Of course if you use a very small return pump or add additional u-tubes so that the velocity slows down enough they can collect air too, but this is much harder to do with the u-tube design. Even in the case of multiple u-tubes the siphon never breaks is all tubes. So you see the real problem is that CPRs don't suck enough.. if they did the bubbles wouldn't collect. If you own a CPR or plan to purchase one against the advice of members here I would highly suggest you build and use the following DIY device: http://www.livinglava.com/diy_water_level_alarm.htm

 

[monkeyboy]

Bluntly, THEY SUCK!

I'd like to see someone keep a consistent siphon w/out adjustment for a few weeks, it really can't be done. A small powerhead w/ a venturi hooked into the nipple at the top of the siphon works well, but spews bubbles into the tank. The hole in the nipple is really small, just a single dump from a yellow tang will get that thing clogged. Clogged nipple = overflowed tank. Stick w/ U tubes unless you can get your tank drilled, but any type of system relying on a siphon requires lots of regular maintenence and is prone to having it's siphon broken.

 

[DK]

After several floods, I built my own powered overflow. The powerhead in the tank has the first problem of possibly not working, second, the line gets clogged because it isn't strong enough to pull through small particles and third, if the power is out for an extended time, the water will back siphon with the tank water level falling to the level at the end of the tube of the powerhead in the tank - is the sump big enough??
I put a maxijet powerhead in a DIY overflow that pulls collected air from the highest point. The powerhead is in the outside portion of the overflow. I also connected an air line to the CPR I still have on my tank(s).

 

[sally1]

I had the CPR 90 for a year and it flooded more times than I care to count. I couldn't sleep at night. Finally I went with a Lifereef overflow and have been sleeping soundly every since.

 

[Pit Bull]

Thanks guys for the ideas and advice where can i look into lifereefs overflows. Could you describe a U-tube more in depth. My tank has been set up for a while so drilling is kinda out of the question. TIA

 

[Pit Bull]

I was planing on putting a refugium under my stand thats why I was looking at overflow boxes. If they use siphon to move water and my refugium is lower than my tank then when i turn of my return pump in my refugium won't water still be flowing from my tank to my refugium? To me that sounds totally unsafe. Any insight on this problem?

 

[fishfarmer]

I think most overflows are designed to stop flowing, but retain the siphon capability when the power shuts off and then is turned back on. If the siphon broke or there was too much air trapped in the tubes, then you may have problems with the tank ovefilling.

Another piece of equipment to invest in is a FLOAT SWITCH for your sump pump. In case your overflow doesn't restart, the float switch in your sump will shut the return pump off before too much water is pumped back to your tank.

 

[wildbill]

I've been using a cpr150 for 4 years now. At first I had alot of problems with it losing syphon. Even when I added a power head to it still would lose its syphon. My sump is about 15 feet below the over flow. The soluction was a add a stronger return pump. I bought a 100rlt and put a ball valve in line to restrict the flow as needed. Now I can lose the syphon all day long and once the pump is swithched back on the force of the returning water moves the air.

If you call the makers of cpr's they'll tell ya the same. cpr150 is rated for 1500 gals an hour. I use this on my 120.

Bill