Give me the good, bad and ugly of CPR overflows

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fishfreek

Aquarium Advice Addict
Joined
May 16, 2002
Messages
2,256
Location
Virginia
Ok, I am looking for an overflow for my 80 gal tank. The only overflows I can find on the online stores are CPR brand. If anyone has had experience with these overflows please post a response so I can make an educated decision about buying one. I am looking for 1100gph flow at the most and 800gph flow minimum.
 
Ya the first one you posted is the CPR.

From what I have heard they acutally "require" a PH to keep the syphon going if the pump stops. I know the "U" or "J" tube style overflows will NOT lose the syphon if a power failure occurs.

Personally I think that is a poor design if this is the case with the CPR's.
 
I'm not familiar with the CPR, but the tidepools do not reqiure a PH to keep the siphon if the main pump quits. It does however use a powerhead to keep air bubbles from accumulating in the tube, and eventually breaking the siphon.
 
LifeReef

I am looking at this overflow now. I will need the dual unit and I expect I will modify the overflow a littlebit so I can remove the sponge's on the back and maybe add a short lengh of pvc to the down flow ports to cut down on noise.
 
I use two overflows on my 75. I'm pumping about 600 gph. One won't keep up. You want high flow through your siphons, that's what keeps them from getting airlocked. I use simple U tubes. Cheap and effective. When I clean one, I throttle the pump back and use the other one.

FYI

Mark
 
Just a thought, but instead of two overflows, couldn't you simply use two U tubes or J tubes in one overflow. I used to do it all the time.
 
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