Hydroid Questions

Never knew about Hydroids these untill today
i have questions
What do the come With Live rock sand ?

How big are they?

are they Harful?

Do you take need to care of them?
and additional Info, i want to learn about these
and or links
Thx;D

 

There are several types of hydroids and they can definitely come in on rocks and sand and corals even. They can be harmful to corals, especially sps and lps corals. Do a google image search for digitate hydroids and colonial hydroids and see if they look like anything that you may have.

 

i would suggest contacting scenario1313 he had to demolish a tank because of the those nasty pseudo-jellyfish.

edit: don't mean to worry you most hydroids simply go away if i remember right

 

i dont have em just wondering about em

 

woa demo a tank??? i have loads of those things on my glass.....