Finding pin holes in a closed loop system

[my2rotties]

Hubby didn't take it apart like I thought he did... prob too early and he played around down there, so I would get off his back. I have a reason to suspect there may just be a Gorilla crab in the pump. I was going to take it apart myself and I thought of Tony's post in the lunge and just decided to leave it be... The strainer will be going back onto it tonight. We took it off since we have filter socks and I forgot about the crab that is living in the sump.