Overflow box

[memer]

I have a glass tank that is not drilled and have been using a second hand overflow box that is rather funky but works. It has began making suction noise that I can't seem to get rid of. It worked for many months without noise but I shut it down while cleaning, flooded my sump, took hours to get started again and now the noise. Husband thinks it is the lift pump. I'm thinking of just getting another overflow box. What brand and size would be recommended for a 115 gallon tank, and should I go with pump or syphon type? Which of these start automatically if there is a power loss?

 

[Chichas01]

Sounds like you have air trapped in the U tube maybe? I never used a hang on overflow box, but I'm sure someone out there has an idea what's wrong. Is it too late to drill for an internal overflow?

 

[memer]

This is an older glass tank and I would be scared to try to drill it. I will eventually upgrade to a larger/better tank but till then I need to keep this going.