CPR overflows

[rennocneb]

Hi i just purchased a new CPR CS100 overflow. Are these self regulating in some way? how do i balance the flow between the return pump mag 7 and the overflow?

 

[1979camaro]

not sure as i don't have one...did the LFs not explain it to you when you bought it?

the beauty of a drilled tank, of course, is that the tank will overflow however much water it needs to (until it can't keep up). I would assume that you will need a ball valve on your return line to adjust for that sort of thing...but i really am not sure

 

[rennocneb]

well the overflow will more than keep up with the retun pump

 

[1979camaro]

well...how is the overflow itself designed? do you have to put a pump on it? if it doesn't have a pump then it shouldn't need any regulation as it will just keep up with however much water the return can throw at it

 

[rennocneb]

its got the aqualifter pump to keep the siphon going but no actaul water pump. i plumbed it with all pvc down to the sump. should the pipe dump the water above water level or below it?

 

[1979camaro]

just below the water line is usually best in terms of minimal bubbles and noise reduction

 

[dbacksrat]

i've been looking at cpr overflows so i might be able to help you a bit

you have your overflow plumbed to your sump with either pvc or flexible tubing...the siphon draws water from your tank to the sump...
hopefully you are using a return pump (which sits in the sump usually) that matches the GPH of your overflow--the Mag Drives are highly rated for a task like this (or Rios if you are a little tighter on the wallet, like me)
as for regulation, i have no idea--maybe a ball valve to stop the siphon while you are servicing the sump--i have no idea how an overflow works when the power is off and the return pump is out--hmm...

 

[1979camaro]

when the return pump shuts off you get the problem of back siphoning through the return line...to solve that you drill a small "anti-siphon" hole just below the waterline in the display on the return line. then, when the water level drops below that hole (but before your sump overflows) the siphon is cut off and no more water drains. i suppose you would want to do the same on the display side of your HOB overflow, but like i said im not sure how these bad boys work

 

[1979camaro]

ok, ive done a little web research (its called using all available resources) and it looks like setting up the return pump so that the intake is just below the optimal water level is the best way to deal with the possibility of a loss of syphon and the subsequent overflowing of the display. this way, even if the syphon is lost all you do is run the pump dry...yes, this kills the pump but it doesnt put 20 gallons on your floor.

as far as loss of pump power the overflows seem to be designed to not flood your sump because eventually (early on if you place the thing right) the tank water stops flowing into the overflow box b/c the return is not refilling the tank

good website here: http://www.tnreefer.com/overflow.shtml

 

[dbacksrat]

wow camaro--great link--my overflow costs ~$80, but if i DIY, it'll be <$20

so, it would be wise to have some sort of regulatory valve on the return pump line into the main tank, not the "in" pipe from the siphon (or does it depend on what is faster GPH wise?)

 

[1979camaro]

if you are going to put a ball valve you need it on the return line. if you put it on the down line it either won't do anything (remember the pump determines how much you put through the overflow) or you will flood the display if you cut off too much flow

 

[rennocneb]

i got it all regulated and working very nicely, only one problem so far the mag 5 pump makes a lot of vibration in the sump and as a result alot of noise is there a way to issolate the pump from the glass

 

[1979camaro]

well, i tried to post a reply but the danged board froze

so, anyway, are you using a mag 5 on the skimmer and another on the return?

for the vibration a pad of silicone rubber will do the job

 

[dbacksrat]

i ended up at kmart tonight and bought the two ice bins needed for the overflow--gonna do it myself--oh yeah

maybe i'll do a step by step build your own overflow thread

 

[dial]

1979camaro....

i have a 90g tank. if i was to do what that guy did in his tank. how biger sump would i need???? is there an effective size (im guessing enough to put a skimmer in it)

cheers

 

[aresgod]

15-20 gallons would be fine

 

[dial]

cool thanks.

 

[wayne]

But the bigger the better in case you want to do more than just the basics in the future.

 

[rennocneb]

im using a mag 5 on the skimmer and another for return. going to step down a size on the return pump and up a size or two on the skimmer