Hydroids-HELP!

[Whatigot]

Originally Posted by trilinearmipmap

I wouldn't use a blowtorch. The water within the live rock will turn to steam, then the rock will explode in your face.

I have a small patch of hydroids which not by coincidence is right under my feeding area. IME they grow with excess nutrients and recede when nutrient level go down.

I find the suction hose/filter sock in the sump trick while trimming the hyroids with scissors keeps them in check. I have some Aiptasia-X but I haven't tried it on my hydroids yet.

although you would have had to introduce the hydroids before they could take advantage of your excess nutrients.
They do not just come out of nowhere.