All is well. I have added a second airstone into my system. The other day it was noticed that a couple of the fish were gasping for air at the surface as well as eating air bubbles. Thoughts were that perhaps there may not be enough oxygen in the water, and that could be another reason for my fish dying.
The fish look happy and seem to be swimming better. They don't surface nearly as much as before and like to chase each other around.
As the days go on I am zeroing in on homeostasis!