Why is my tank overflowing?

adrock16

Member
I have a 55g tank with a 20g sump underneth. The outflow pump is a rio 2100 and the overflow box is a CPR 400. The tank started overflowing about 2 weeks ago. Its all been running fine for about a month. Then last week I noticed it was spilling over the side. My lfs said maybe the overflow box had air in it. So i bought a pump to get the air out and it was running good for about a week then started flooding my kitchen again. Anybody have any ideas why this is happening?
 

philgmiami

Member
MAKE SURE THAT THERES NO KINK IN THE LINE GOING FROM THE OVER FLOW TO THE 20G SUMP..IF THE LINE KINKED OR CLOGED THAT WOULD CAUSE YOUR WATER FROM YOUR SUMP TO GO IN YOUR MAIN TANK MAKING IT OVER FLOW..... IF YOUR LINE IS KINKED FROM YOUR RIO2100 IT WILL CAUSE THE SUMP TO OVER FLOW.............THATS MY ONLY THOUTS OF OVERFLOW'N ANY WHERE
 

nm reef

Active Member
I've never used a CPR overflow but many report problems with them....it seems air bubbles tend to develop which restricts and even stops the flow. I believe they require a small pump to constantly remove the trapped air or they don't function properly.
I prefer LifeReef hang on overflows...much better design and no flow restriction problems.
 

acrylic51

Active Member
NM is right they do have problems with developing air that will slow down their flow....I was given one to play with from a friend, and even with a pump and PH doesn't cut it it still will get air trapped inside of it......It's a neat design, but to be totally honest it's a misclaimer on the manufacturers part.....They even say about using a check valve or something to eliminate the air, and that doesn't work either....
I would honestly check to see if you have air traped and even check your drain lines to make sure nothing is clogging them.........
 

adrock16

Member
Thanks everyone for your speedy replies. I had the owner of my lfs come by and look at what I was dealing with. He pretty much said the same thing. Im going to pick up a pump and hopefully this will solve this little problem. Thanks again
 

bigb

Member
The pump is definately needed, especially to restart the siphon after a power loss. I have used a cpr102 for over a year now w/o any problems. You will need to make sure you do routine maintenance on the air line, the air pump, clean the sponges in your overflow box, clean the fish screen if you use it. Any small build up in any of these parts will slow/clog the overflow and possibly cause flooding.
 

eel

Member
i am having the same problem,what kind of pump and does it conect to the air line on top of the overflow
 

bigb

Member
google aqualifter by TOM. ~$12.00. comes with airline and it connects to the

[hr]
on top of overflow box. You let it run constantly.
 

bigtyguyy

Member
instead of buying one of those pumps to just sucks the air out i would try hooking an air hose up to the

[hr]
on the overflow and the other end on the air intake on a power of yours. Try that before buying a all new pump
 

adrock16

Member
so far i have tried a rio 60, which sort of worked. Now I am trying amaxi jet 1200. It was working fine for about 3 days then started to overflow again. I think the hose had a kink in it and the water wasnt flowing smoothly.
 

fishieness

Active Member
is it overflowing out the side ofthe overflow box or the actual tank and sump?
cause you should have enough water for it to overflow out the sides of the extra space in the sump, and the baffles should be high enough so the pump will stop pumping before the tank overflows, and the teeth of the overflow should be high enough so that it wont drain enough water for the sump........ ordid i misunderstand where it was overflowing?
 

adrock16

Member
Fishieness it was overflowing at the main tank. I think the problem is under control now. I installed a maxi jet 1200 (free from my lfs) about three days ago and its been fine so far. I also took BigB advice and cleaned the sponge and fish screen. Thanks everyone for the help.
 

bigb

Member
Double check you oveflow box, I can't find a cpr400. What is it rated gph?
Also what is the rio2100 rated for gph?
You may have too large a return pump for your overflow. This would also cause the main tank to overflow.
 
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