hydroids

Hydroids are part of the jellyfish family. They are mostly harmless creatures, and they usually appear in new tanks. It's something that you don't really have any control over. Most of the time,you would just run the mag float right over them. lol. I have never heard of hydroids being bad for your tank.... So, I hope others can join in and let you know why, because I certainly don't. lol 

Which hydroids are you referring to?  Colonial (sessile) or hydra (motile)?

Hydroids typically bloom due to an abundance small, usualy live, food items.  The hydra typically just go away on their own, the colonials don't really hurt anything unless they're in proximity to a sensitive coral.  None of them can harm fish, with the exception of fry.

You can get rid of them by treating the tank with H2O2 or with Fenbendazole, but inverts don't like the treatment very much.

I was told they were very bad for seahorses, otherwise harmless

If they look like snowflakes they're hydroid jellyfish.  They're harmless and usually disappear on their own.

Quote:

Originally Posted by Flower 

I was told they were very bad for seahorses, otherwise harmless

Bad for zots and fry (they can be stung to death or develop bacterial issues from a sting)...adults are fine.  I know a very experienced SH keeper who used to siphon them up into a tube using his mouth (like the old school pipetting practice), accidentally got a mouthful and they stung his mouth!

1guy,

Do they look like this?

Those are hydroids??? Attached like that? The ones I THOUGHT were hydroids actually looked like a white snow flake on the glass of the tank or free floating.... no tubes attached to the rocks. So was I seeing some free floating stage of the critter?

Quote:

Originally Posted by Flower 

Those are hydroids??? Attached like that? The ones I THOUGHT were hydroids actually looked like a white snow flake on the glass of the tank or free floating.... no tubes attached to the rocks. So was I seeing some free floating stage of the critter?

 

What you're seeing are hydroid medusae (like little jellyfish), the 'droids in the pic I posted are colonial 'droids.

I HAVE to say this..."these arent the 'droids you're looking for"

Quote:

Originally Posted by saxman 

What you're seeing are hydroid medusae (like little jellyfish), the 'droids in the pic I posted are colonial 'droids.

 

I HAVE to say this..."these arent the 'droids you're looking for"

 

LOL...cute.

So just making sure.....this little snowflake type of hydroid won't hurt my seahorses?

Quote:

Originally Posted by Flower 

LOL...cute.

 

So just making sure.....this little snowflake type of hydroid won't hurt my seahorses?

 

Not adult large species (erectus, reidi, kuda, pots, etc), but they can kill fry and zots (dwarves).