CPR external overflow boxes

O

one eye

Member
Has anyone else had a hard time with the cpr overflows? Mine keeps letting an air pocket build up inside the siphon until the pocket gets big enough to stop the siphon. That, as you have probably already guessed, makes a big mess. On the good side it causes me to do frequent "water changes".

Any ideas would be appreciated. I gave it some thought and decided I'd rather do scheduled water changes as opposed to surprise water changes.

Thanks,
Darren
 
wooddood

wooddood

the wood dude
sorry to here that.i just bought a cpr overflow on e-bay this week.i read that these were some of the best overflows on the market.anyone running these have any pros or cons on yours? thanks dave.
 
reefrunner

reefrunner

Contributing Member
Any ideas would be appreciated.
Click to expand...

CPR recommends using a powerhead (with the airline/venturi) to remove the accumulating air bubbles. Personally I would get a different overflow, I have run several for years on end without this being an issue, it is common with CPR overflows.

Here is CPRs troubleshooting page on their model CS50, not sure which one you have, but the air issue should be the same no matter what model. http://www.cpraquatic.com/support/troubleshooting-CS50.html
 
O

one eye

Member
reefrunner, thanks for the reply. I have it connected to a power head. I actualy had better luck running it opposite the venturi. I hooked the airline to the intake of the power head instead. It only delays the inevetable. I've tried all cpr how to fix our product advice and still have the same problem. This leads me to believe that somewhere there is some kind of a fault in the design.

What type of overflow are you useing? I'll have to try one out!

Thanks
 
M

MoJo'sReef

Member
ill tell u a secret i found out
i have a cpr overflowbox 1400 and im running a mag 2400 pump pushing 1800 gal threw it and i dont have a power head on it what its doing is forcing the air bubbles threw it i have so much water flow that it cant build up give it a thought it might work for u ive ben running this over flow box over a year like this with no probmes what so ever
i love it
just my .002 here Mike
 
J

jupiter

Guest
I used the 50 and 100 models and I never had a problem. I used a Hagen 402 PH with them and the PH pulled so much water out of the OF box that the air never built up.
 
reefshadow

reefshadow

Member
hi, One eye-

I use the model 100 and use a power head that pumps 550 gph to bleed the air out. I look at how much accumulation there is daily however because there have been times when the powerhead does not work well, such as when it is getting clogged or when the screen on the overflow needs to be cleaned, and I have narrowly avoided floods! (and with an 80 gallon sump that would be no joke).
My next project is going to be putting a float switch in the sump to shut off the return pump as a safety.
I have heard the same thing that Mojo states, with the larger overflows you can get water moving through fast enough that the air doesn't accumulate at all. I have a 1400 waiting to be installed but I still have to buy a larger return pump for it.
Maybe a larger powerhead coupled with a float switch on your return pump would be a good investment for you.
Of course a drilled tank is the best solution!

Good luck!!!!
Becca:)
 
Dennis7

Dennis7

Member
I use a cpr overflow on my tank right now with a rio 600 venturi.
I have found out that if you have the overflow box slightly unlevel, up on the nipple side, the air will go to that corner and pull out easier. I haven't had a problem with mine yet in over 10 months. I will stop using shortly only because my new tanl is drilled. Hope this helps you some.
Dennis
 
wooddood

wooddood

the wood dude
thanks all now i feel alittle bit better.mine will have plenty of flow and sounds like thats the key.thanks. dave.
 
O

one eye

Member
Hey thanks for all the replies guys! I am still a little confused as to why I'm having trouble. I'm using a Mag 18 for a return pump (it's only a 45 gal tank)and the air line is hooked up to a MJ 1200. I have also tried tilting it so that the air bubble would go towards the air line and that didn't work. I talked with my lfs and CPR is suggesting that an air pump be used. An air line from the CPR unit to the air pump then from the air pump to the power head. The air pump is inexpensive and small. It sits on the back cover of the overflow.
wooddood, you may want to pick one up as a precaution. Apparantly this is a common problem. CPR has a little sheet printed up showing which pump and how to attach it.
 
jks1

jks1

Member
you would think if they knew this was such a problem they would fix it or at least include whatever auxiliary equip you need to make it run correctly with it....
 
wooddood

wooddood

the wood dude
i just looked at the auction i won and it said it comes with a aqualifter pump.i should be getting it next week and l will let you know how its working.thanks all.
 
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