ID Please
 

I found this patch of what I think is some kind of algae on the back side of one of the rocks in my tank.... Anyone have any idea on exactely what it is? Not a great pic but......

http://i432.photobucket.com/albums/q...knownLarge.jpg

Cheers
Lawrence

Can't recall the name of them, but they grow really fast and you don't want them. I'm having a hard time getting rid of mine.
Good Luck.

Looks like Hydroids to me. You're in for some problems... they have a nasty sting and are nearly impossible to kill while still in the tank. A buddy of mine blowtorched his rocks to get rid of his.

Rock is removed!!!! I will let it dry out for a week or so and then try it again.

Yep hydroids as they said. I would blow torch it if I were you, it damages the function of the rock less than leaving it out to dry for a week, and ups the chance of actually killing those little bastards. They are tough!!

My new weapon of choice against hydroids is a soldering iron. I remove the rock and apply heat. It gives off the most wonderfully satisfying sizzle as they boil and the best part is that I can just put the rock back in the tank because it only affects such a small targeted area (unless the hydroid patch is enormous).

Oooooooo good idea!!!

I have torched the rock and put it into the sump for a bit. I will keep an eye on it before putting it back into the DT. Thanks for the help.

Cheers
Lawrence

I had a bunch of this stuff on some of the liverock I acquired from a couple used tanks I bought to fast forward my 90 gallon...
I just used a butter knife and screwdriver to chisel it all of, it came off pretty easy, almost like they weaken the rock they live in or something....

Soldering iron!! What a great idea.

I've heard of people having some minor success epoxying over hydroids, but in my case, they just grew over the epoxy. Yay. Blowtorch, soldering iron ..if the rock is structural and can't be removed maybe boiling water in a syringe? (I've had some minor success zapping valonia and bryopsis with that trick)..