Do reef/ fish tanks and cats mix?

[SeaHorse_Fanatic]

When we moved to our present home, I set up a 165 6.5" acrylic tank here (where my brother in law was living) so that the move would be as easy as possible. I slowly filled the tank with half old water and half new water. What my bro-in-law didn't tell me is that his stupid cat jumped in one night and its flea powder got into the water. Nope, thanks buddy. That easy move from the old place to here went smoothly as far as transporting the fish over, but the cat's flea powder killed off a lot of the fish. He only fessed up when I noticed scratches on the inside of the acrylic tank and it was his gf who mentioned the flea powder. So when Felicia mentions cat, I tell her sorry, but no. Besides we cat sat for a friend for 3 weeks and the bloody cat kept running away from Felicia & would try to scratch her if she got too close. Not a fun experience and couldn't wait for my friend to come back from Taiwan. I've dog sat before and that was a far better experience.