Same thought as Terry. I have housed 4 yellow tail and 2 Hippo SH with many Zoa frags and green palys before..no issue.
IMO, It's maybe other creature in your tank attack your sleeping SH in the nite.. !
He will quote you estimated price on the phone if you able to tell him your chiller problem.
Price wise quite reasonable. He charged me 90 for changing fan motor and blade few month ago..
Btw, he is a very nice & friendly guy ... !
I have been using Amin since 13 this month after your review. For polyps extension confirm but didn't see color up yet perhaps it's too early to say.... !