Save ur money bro. I tried them and they were so shy and delicate so I just bought a bunch of emeralds and they took care of an infested 5 footer in a couple weeks.
My pithos from reefcleaners always arrive DOAI ordered 5 from reefcleaners because my emeralds weren't interested in the bubble algae. I threw some clumps of bubble algae in a container with the Pitho crabs and they all immediately started munching on it. They took care of my bubble algae in my tank. Lost 4 of them during the molting process due to parameters being off, but still have one in my tank and no issues with bubble algae despite lots of it in my refugium.
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