Please help me identify these?

[Jeramy]

Been doing epic battle with these tiny white algae like substance on my rocks. It grows really fast and the bigger it gets the more complex the structure. It cleans off very easy and have been siphoning it out and scrubbing with toothbrush but the next day it is back. I don't think it is hydroids. It seems more like an algae. Here are some not so great cell phone picks.

 

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[Emerald525]

Jeramy I still think they are hydroids. The white ones can be filamentous and resemble algae.  Google white hydroids and you should find some pictures.  From what I have read about them, they will eventually die off but in the meantime they can sting or irritate coral.

 

I had a few in the sps tank but they did not take off too much as I had a lot of flow which they don't like.

[Paratore]

Use a flashlight and look at them when the lights are off. If they get long and have "sweeper tentacles" then it's hydroids for sure. Had them once and eventually they all just died off.

 

 

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[Jeramy]

Thanks I will address them with flow. I was not keeping detritus removal from my rocks and had a lot of accumulation build up have started turkey basting my rock and have remove a lot of waste build up so this is will help did some more research and saw that people reported sea hares eating them as well might look into a sea hare rental =)