Emerald Crabs

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farid2544

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Apr 5, 2012
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Tacoma
Just got back from vacation and came back to a bloom in hair algae. We have taken it out manually but I want to get emerald crab to make sure it stays down. I have a 90 gallon mixed reef tank with only 4 small fish in it (2 clown, 1 goby and 1 6 line wrasse). How many emerald crabs should I have and what is the maximum that i should have? I know in order to keep my reef safe we have to make sure they are well fed.
 
Dont know that emerald crabs or tangs will eat hair algae. A Sea hare is the best bet, but would need to be passed on to someone else or back to the LFS when the algae is gone. Continuous manual removal will help. And blow it out to get all the detirtus out of it, because I believe it feeds off of that.
 
My emerald does eat hair algea. Although I do hear some will and some wont, gotta love that. Good luck with the battle :)

I only have one in there and she knocked it down with the help of my bissletooth tang in about a week. It was only a small outbreak and it was at month two so I think it was the last part of my cycling prosses. My tank is a 125.
 
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I had emeralds take out about 90% of my GHA fields.... the bad part about them is that they require calcium like any other shelled invert. They molt frequently and have a tendency to go after your livestock if they can not find food. Fish that are on their death bed usually sink to the bottom where a emerald crab will grab them and start eating it before they die... they also do this at night.... they will find fish while they are sleeping and take them out.

As for tangs... most tangs will nibble at small amounts of GHA. Typically a bristle tooth type tang (Yellow Eye Kole for example) will mouth the rock work. Yellow tangs aren't considered bristle tooth but they do nibble at it too.... I would just beef up your turbo snails.

As for a Sea Hare.... I wouldn't purchase another after loosing a few too many.... I would borrow one from a friend...
 
+1 on a Sea Hare, the very best at ridding your DT of Hair Algae IME. I had a severe outbreak this Winter in my 125g from running fallow, it's amazing how much algae will grow when removing four Tangs from a system. Five sm/med Hawaiian Sea Hares wiped it out in a few weeks. Some Cowries and Lettuce Nudibranchs are other good invert choices. As for Tangs, they will all consume some Hair Algae and after placing my four back into system whenever I rearranged any aquascape and exposed some HA they quickly devoured it.

Cheers, Todd
 
I have emeralds and they do a great job - the females are much less aggressive than the males with the fish - I don't have problems with them going after the fishies at all.
 
I have a male and I call him ol' crabby pants. I feed him usually once a day with either a shrimp pellet or a small piece of brown seaweed and he still keeps the algae down. He's a pig. Never has bothered any of my fish except when I had my tang, the tang would mess with him, just like he was teasing the crap out of him. Other than that, he hasn't caused any problems. He has been in the tank for over a year now, my oldest resident.
 
I say start at the root of the problem, if you take the algaes food source away it goes away. Just my thought.
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I have one Emerald Crab in my 90. He's done a great job eliminating the last little bit of algae I had in my tank. I don't see him very often, maybe once every couple weeks. Haven't ever seen him pick on any fish and i haven't noticed and wounds on them either (i have a sixline wrasse, 2 clowns, hippo tang, and a coral beauty angel).
 
Within an hour of putting my new emerald crab, he plowed thru a small Forrest of hair algae.
 

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