Hydroids-HELP!

[Whatigot]

Originally Posted by i have crabs

i have a few small patches that haven't caused any problems but when i was joe's juicing some aptasia i gave them a squirt and it wiped out a big strip right through the middle of the patch

They'll be back.
I have had some success with taking the piece of rock out and running HOT water (boiled R/O, but I don;t see why tapwater wouldn't work as well) over the affected area.

Every time I kalk, the hydroids come back like raffis cat.
Been 2 weeks since I tried the boiling water method and they have not returned as of yet.