Weird flakes all over tank

[roblox84]

I'm currently moving corals from an old neglected frag tank into my main display but I'm worried about these weird brittle flakes that seem to cover the live rock and bottom of the tank that I don't want to introduce into the other tank.

Some of them are hard to blow off my rocks but I can scrape them off with my finger and somehow they make it back up onto the rock. I took a few out and was able to crush them with my finger nails very easily. Is this just some kind of free flowing calcerous algae? At first I thought it might have been coraline but that shouldn't appear back so fast and usually it's not circular disk shaped that blows off rocks with my baster.

 

[Mastiffsrule]

Hi,

Maybe spiroid worms. Hard for me to see in the pics

 

[roblox84]

Unfortunately that's the best pic I can get. If I remember tomorrow I'll try to pull a few out and snap a pic although I did check and it definitely wasn't spiroid worms.

These things in my tank are about as thick as a piece of paper maybe even thinner and don't appear to be living at all. It looks like some calcerous disk that multiplies quickly. I tried all sorts of keywords in Google and unfortunately everything I saw just didn't look like this.

It doesn't seem to do anything to the corals but I'm worried that if 1 or 2 are hiding in a frag that I put in my main display that whatever it is will multiply in there too.