these guys just showed up they are white and almost look like plants or something...they scrub right off but come back....also how do you get rid of them?
The come in on live rock or frags.. they are good to have. They won't stay there forever though. They only multiply like that when your nutrients are high. They will disappear as you lower nutrients. I find them here and there in my tank from time to time. Great filter feeders and don't harm anything!
I let my girlfriend feed my tank in the mornings and ended up with a ton of these things I guess that's what I get. They are harmless just filtering out extra nutrients if they really bother you then you could pick up on water changes and filter maintenance.