What is the best overflow box???

hawkfish203

Member
Thats what i'm using now is pvc but, it sucks when I have to shut it off for a water change I have to get it going again every time. The CPR looks easier.
 

reefraff

Active Member
If you use the CPR make sure you run it with an Aqualifter pump hooked up to it. I tried every way I could think of to keep the siphon alive on my last tank and couldn't do it without a pump hooked up to it.
 

monsinour

Active Member
aqualifter should be on at all times. I have thought about some kind of valve in the tubing. Turn the pump on to start the syphon and then close the valve and turn off the pump. Anyone think it will work?
 

reefraff

Active Member
Aqualifters might be crappy but they keep air from acumilating in the top of the CPR overflow. I know some people have hooked up the venturi of a small maxijet to them which will work too. What I experienced was there would be enough air in the overflow that if I stopped the return pump it was 50/50 whether or not it would break the siphon.
Also heard of people running airline from the nipple on the overflow down to the sump and setting that up as a siphon. Again that works but if you get a power outtage that lasts long enough it's going to drain the tank far enough to break the overflow siphon.
 
S

saxman

Guest
I'll ALWAYS go with a drilled setup first, but I prefer the U-tube type overflow boxes to the CPR type. All you need to do is keep the U-tube clean, but if you ever do get a bit of air accumulation, all you need to do is knock it loose and it will clear itself. Some folks add an airline valve to the top of the U-tube to make priming it easier, and this can also be used to suck any air accumulation out, altho this is a rare thing IME.
 

cam78

Active Member
When did they stop using the u-tubes? The design I have has the U-tubes. How does it work now?
 

btldreef

Moderator
The entire piece is basically a U Tube now and has a continuous flow, but I had nothing but issues without running the lifter pump 24/7 on it as do many other people. I think if you go to their website they have videos of how the new models work.
 
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