What’s going on with my tank

[clowntank]

Hi everyone!
I’ve been running my 15 gallon reef tank for about 4 months now, and a month ago I moved it to my college town, and things settled in and were great. I noticed some brown on the sand; thinking it was diatoms, I let it be and was just planning on riding it out. I recently started to notice my snails were very unhappy, which I know can be a symptom of Dino bloom, and my corals also look mad (I have a leather, a hammer, and a GSP). I also noticed some bubbles coming from the brown powder on the sand, which is steering me toward Dino’s. I’ve attached a picture below. Can anyone give any insight?
Thank you so much!

 

[Waters]

Hard to tell from the picture but it looks like a combination of cyano and diatoms.

 

[BairCorals]

Diatom bloom I'm guessing, do a 5gal water change and siphon a bunch out then do your tests to make sure things are happy. When I see corals retracted I always check my salinity, sometimes it's all I have to do to make them happy again.