Is this regular film algae...I am confused

Ok so I was looking around to try and figure it out, and the closest I've gotten is green film algae. But this stuff is weird it like creates like a mat on the floor. Help would be awesome. I check everything and its normal expect I don't have a test for my alkaline because I ran out like 2 weeks ago and haven't gotten around to it. Also I have the lights on for about 9 hrs a day is that too long, (PC lights, 24 gallon tank)
Much love

 

That looks IMO like usual build up on the sand. What kind of CUC do you have? 9 hours is not too much light.

 

about 4 Margarita snails,3 bumble bee snails, 3 red leg hermit crabs, yellow watchmen goby (idk if that counts but he sifts the sand alot) I had a few more red legs, but i saw them picking at my green star polyps ( and eventually killed them) so I got rid of them. Are there better types of hermits?

 

Margarita and bumble bee snails are not good snails for a reef. You could try reef cleaners.org and they will be able to get you a good cuc for your tank.