what type overflow box??

r2odie

Member
What is the best type of hob overflow box? u-tube or cpr (siphon) type? please let me know any pros/cons on any kind because I am setting one up on my 37 gal. and I need the most leak/flood proof possible on our new wood floors! thanks!
 

hot883

Active Member
If you do not fill the sump or refugium up to fall, either one WILL NOT EVER FLOOD. As an example; my sump/refugium is only 1/2 filled. In the event of a power outage, it will drain the main tank until the overflow box is no longer underwater. That will cause my sump/refugium to fill up to about 2" of the top. As soon as the power comes back on the sump/refugium will go back to the normal level and the "U-Tube" will start suction again. (continuous syphon) Hope that helps. Barry
 

stanlalee

Active Member
U tube is much more reliable IMO. With the CPR style if the air pump fails, you fail to use it (sold seperately even with the knock offs) or it fails to come on/malfunction upon restart (power returning) the siphon will break and just the design of it in general (the size of the passage being continually siphoned) makes it easier to break the siphon. No such issues or additional equipment with a U tube. as long as the actual U tube is long enough (below the drain bulkhead in the back and near the bottom of the overflow box in the tank) it wont break siphon (easier to maintain a siphon thru a 1-1.25" tube than the CPR style maze).
Cons of the U-tube for me is starting the siphon usually ends up with a wet back wall, occasional tank water in my mouth and usually this repeats itself a few times before I am successful. CPR claims theirs flow more water which is believable (and irrelavent) based on the designed (and also the reason the siphon is much easier to break).
Beware of outragous prices! $50 e-gay overflow boxes work just as well as $120 name brand ones. Mine $62 shipped e-gay overflow and included 3ft drain tubing. never breaks siphon and workmanship is perfect. It wasn't a fluke because I have two (one for 30g and one for 100g) and they are identicle.
here's a pic and the line shows where the water drops to when power is shut off. as long as the U tube remains below the water line on both inner and outer boxes the siphon remains intact and functions as normal when power is turned back on. If you dont want to clean algae off it often try to find one with dark colored acrylic instead of clear.
 

crf230

Member
I like the cpr type. I had a u tube one and got rid of it because it looked to big and ugly for my 29 gallon aquarium.
 

cgrant

Active Member
I am not sure if drilling your tank is an option but after having one with overflows I can tell you they are very quiet and i wont ever have another tank without them.
Most LFS that sell saltwater will also drill tanks, I would do that with the durso standpipes but its your tank!
 

r2odie

Member
CGRANT -
Do you know what is involved in drilling a tank that is currently set up? Like how much I would have to drain it, how risky it is, etc. my husband has never drilled glass but is willing to try if I want. I saw an acrylic overflow box on ---- that looked like the whole was drilled maybe 4-5 inches from the top but I have no idea. Any suggestions??
 
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