Pretty Sure My Sump Is Leaking

[joeyprice]

All the plumbing from the overflow and return is dry, but there is water under and around the sump. Not enough to leave the stand, but more than there should be I think. I dried the are all around it to see if/how long it takes to come back, but I'm pretty sure I'm going to replace it. Is there an area where acrylic sumps are prone to fail, like corners? Is there a method to rule in/out a leak?

 

[joeyprice]

Found it. Missing O ring where overflow meets sump. Very slow leak, but I'm pretty sure that was it.