3 little aptasias in a little tank

[Maxi]

I never thought one of these would ever pop out in my tank after 6 months of owning it.

This little 3 gallon, stopped doing great since the little fish that lived in there jumped out. Coraline algea also stopped growing since that fish died leaving his pistol buddy in there only. A bunch of bubble algea came out too.

I'm wondering how can I kill those 3 aptasias before they become really bad, and if the fact that the little goby jumped out is the cause for all of this happening. Or is it because I feed a lot less now?


Thanks
-Maxi