whats wrong with my sponge? :(

[m_shuta]

while on vacation, we had a friend watch our tank. it hot very hot in town & our tank temp ended up reach 90+. it ended up killing our lionfish & the death of our lionfish killed a couple corals. our fish survived and all of our inverts. I noticed our Lunar sponge started to expand & it's not stretching even more. what's wrong with it? I've asked alot of people & everyone's baffled!! thanks so much for any input!