The Electric Blue Hermit Crab is a superb algae eater, and will even eat filamentous algae and cyanobacteria. It is very useful in keeping reef aquariums clean and free of undesirable algae. As they grow they will need larger shells to take the place of the shell they outgrew. Place several old snail shells in the aquarium where the hermit crabs can get to them when the time comes to move to a larger shell. Maintaining proper Ca, Alk, & Mg levels is important for growth of their shells.
Don't forget about your water parameters when combating algae blooms. Water chemistry is every bit as important as a good clean-up crew.
It is important that proper calcium (420-440 ppm), alkalinity (8-9.5 dkh - run it 7-8 if you are carbon dosing) , and magnesium levels (1260-1350 ppm) are maintained. Raising magnesium levels gradually up to 1400-1600 ppm can help to combat algae outbreaks, just keep CA and Alk in line as you raise the Mg. Nitrates should be below 10 ppm and phosphates should be below .10 ppm. We recommend doing a water change when Nitrate levels rise to 10 ppm. It is important to replace your phosphate media when phosphates rise to .10 ppm. Media Reactors make the most efficient use of your phosphate media by fluidizing it.
Vivid Aquariums uses and recommends dosing pumps to automate the dosing of additives and keep your levels more constant. A dosing pump can alleviate the chore of manually dosing your aquarium with Ca, Alk, & Mg 2,3, or 4 times per week and will benefit your aquarium by keeping your levels constant through frequent small additions of Ca, Alk, & Mg. Our tanks all progressed when we switched from 3 manual dosings per week to 70 automatic dosings per week and we got a lot more work done.
If no algae is present in the aquarium you may supplement the Electric Blue Hermit Crabs' diet with live macro algae, dried seaweed (nori), and mysis shrimp.