snot loooking white-ish blob with several arms

Hello. On a few of the live rocks we purchased from someone’s tank there were snot looking blob. Really looks like white snot. After a few weeks have noticed it has grown larger and spread out and there are more of them on other rocks too and now they have several arms, upwards thin cylinder shaped...

Got some coral on rock with hair algea all over

I picked up some zooanthids, xenea, leathers, candy canes. Anyways, the rocks that these are on are covered in green hair algae. I fear putting them in my 99.99% algae free tank. I don’t want this algae to spread to everything in the tank obviously. I keep my nitrates and phosphates down which is why...