Digitate Hydroids


Reefing newb
Hi all,

Noticed last night i have a couple Digitate Hydroids in my tank. I have been doing some research on these pesky critters and I am getting mixed reviews. I looked on Xtalreef and it states they are bad, but then I have seen things come up that that are ok. I know the multiply quickly so I want to get a handle on them ASAP if I need to. I can't take my LR out and scrub it because I have star polyps on it, i'm worried about them too if the hydroids sting as bad as stated.

Side note: I did just lose my Lawnmower Blenny and now I'm suspecting the hydroids as the culprit.

What I want to know is how do i get rid of them?

Chichimom recently dealt with these and had a thread on them - you might want to run a search of the forums to see what she did to battle hers.
They are tough pests to get rid of -- some of the worst. And don't be fooled, they are bad guys. They will sting and kill anything they come in contact with.

Usually the only way to eradicate them is to remove and kill the rock they are on. This is problematic if they are on more than one rock, but if they are isolated in one spot, that will be your best bet.

I know you have star polyps on the rock with them, but in my opinion, the loss of the star polyps is a small price to pay to get rid of these guys.
The one thing i do have going is that the polyps are mainly attached to a small piece of stone, they just started expanding and growing on my LR. So I could just pluck them off and move them so I don't lose the whole colony. Is it recommended then just to boil the rock in RO water? and for how long?
Star polyps are pretty easy to remove if you take a razor blade and scrape them off beneath their mat. You can then use super glue gel to attach the mat somewhere else in your tank.

You can either boil the rock or just let it dry out. I had to boil rock because of pests before, and I let mine boil for 15 minutes or so. That's probably overkill -- I can't imagine anything would survive that.
yea. i'll do that as soon as I get home today. probably a dumb question: Do I need special super glue or epoxy to reattach them?

Thanks a ton
No, you can use regular super glue gel from the hardware store, grocery store or dollar store. It has to be the gel kind, though. The regular kind is too runny. I like the Loctite brand the best.
I had these on my lr when I started my tank a couple of weeks ago - after researching I decided to strip my whole tank and dry everything out...

I was still only cycling though so didn't need to worry about fish or coral - just stripped the tank and started over :(

Good luck with your ones - hope you find some better option
If there is only 2 hydroids why dont you just take a hammer and chisel and chip off the piece they are attached to? A lot easier than boiling.
hi Salty B. That was a great idea, I was going to do that, but then noticed a couple more much deeper in the rock, so i've decided to just boil the entire rock again. More of a pain, but I want to make sure they are eradicated.
I have hydroids pop up from time to time. I got them as hitch hikers from an LFS down state, not happy. My rocks are hard to remove, so I boil water and use a syringe to blast them with boiling water, works like a charm!
i take the rocks out, then burn the hydriods off with a candle lighter or blowtorch. thatway you don't harm the rest of the stuff.