I use the 1mm size.
Here he is today in his rock.
He is in a large reef .
I had anotherone in my other reef with some 6 in plus maximas with no issues
but every fish can be different. If someone says they seen them nip clams you need to monitor.
Found this at aquacon site:
Tribal Blenny
Atrosalarias Sp.
Great for algae control
Description: Brand new for the aquarium trade, another interestingly marked algae blenny. This one is collected from the waters off of Sri Lanka. Unforgettable warpainted accents on a beautiful royal blue background make this a must have for the aquarist looking for unusual but easy to keep saltwater fish specimens. Combine the incredible markings on its face with its great personality and it becomes a must have.. The Tribal Blenny will add both visual appeal and a great algae control specimen to any marine aquarium its placed in.
Recommended Tank size: We recommend a minimum of 20 gallons with live rock, and it is best to house singly unless kept in a larger aquariums.
Feeding and Diet: Loves natural algae to feed on, the diet can be supplemented with vegetable matter, spirulina, and herbivore preparations.
Level of Care: Easy
Reef Compatibility:Very good reef or community fish.