BC-Axeman

My hermits only eat things that are dieing anyway. I have had a dozen snails for more than a year and had a crocea that survived about five years with a bunch of hermit crabs.
Algae will die off if you get all the nutrients out of the water. Starve it down. Cleaning, filtering, water changes, live stripping by growing algae in the refugium and throwing it away, etc. The removing the rocks and scrubbing helps by taking away material from the nutrient cycle.