The only sump I have had leak, was a cheap poc, that cracked. Thats the last time I used some cheap glass sump.
I have seen hang on,s leak though. And its not cracking but overflow cups. Most of them are not sealed around the cup, although the high end skimmers are pretty close but can still leak. The better ones have overflow protection with the return tube, which is good as long as the water level does not reach the top of the skimmer body.
Has anyone looked at Lifereef,s hang on skimmer. Except for the pump in the water, very impressive looking. Shuts down in case of overflow, through the air intake.
If you find my Tunze 9010 review here, you would see I was very happy with it, except it sits in the tank. But skims excellent and is fool proof. NO OVERFLOWS.
