CPR overflows

[loganj]

Does anyone have any experience with CPR overflows? They look like a good design to me, but I have heard bad things about them also...like they are bad to stop working. I wonder if the folks who have had bad luck with them were using a Rio PH? I think I'd use a Maxi Jet instead. Anyway, I was thinking about ordering one from Ameka Aquatics and I wanted to get some opinions first. Thanks in advance.
Logan J

 

[reefrunner69]

I have heard horror stories about them, cause of power outages. If the ph doesn't come back on....water on the floor. I do agree a maxi jet would be a better choice, but those fail occasionally also, what do you do then? I prefer an overflow that incorporates a simple J tube or a U tube. Curious though logan, why don't you just make an overflow? The one on my fuge works great.......

 

[SW Beginner]

As well I have heard bad things about them. Could look into getting one from LifeReef for not much more.

 

[loganj]

Curious though logan, why don't you just make an overflow? The one on my fuge works great.......

Well...I'm lazy and I'm worried that I wouldn't build it large enough to handle the flow. I would really feel better with two overflows I guess. I have a outer box with two 1" drains and I think I can cram two 1 1/4" U tubes in it. I'll have to build the inner box though. You think that will handle a Little Giant 1200gph pump?

Perhaps I misunderstand the design of the CPR overflow. All my overflows have a hole drilled in the top of the U tube with a piece of acrylic air line glued in. A piece of vinyl tubing is run from that to the venturi on a PH. Since the end of the tube is underwater, you don't lose the siphon when the pump shuts off. Also, a Maxi Jet 1200 will restart the siphon if it's lost...I think a 900 probably would. This keeps the air bubble that always seems to form in the U tube under control also. Am I missing something? It has worked great so far, but I may have set myself up for a flood and not even realized it.
Logan J

 

[reefrunner69]

provided the tube doesn't lose siphon that is fine. But if it does (which I've read ***I have no first hand knowledge, I've never used a CPR overflow*** they have a tendancy to do) lose siphon and the ph fails to start................

 

[loganj]

OK...that isn't really a problem with the U tubes, as I'm sure you know. I had never seen one of the CPR's up close and didn't really know exactly how they were designed. I have used one of the Tidepool overflows and it was a constant problem...very noisy too. I'm thinking they may be of similar design. I guess I'll try the external box that I have and build an internal. I can always add a smaller one if needed.
Logan J