I think it might be coralline?

So my tank has been up for about 5 months, but has been kinda torn down and re set up 2 times after the initial time due to moving. (most everything kept wet and re set up asap) Anyways when the tank was set up it was mostly base rock and seeded with a little bit of live rock. Now most of the rock has started to turn dark green and a lot of little red spots. I think the green rock and red spots are coralline algae but was looking for a second opinion. I have already had green hair and cyano but both didnt make it through the moving process. My calcium levels are quite high somewhere in the low 500's. I do not have any corals at this point, i do not dose, and do regular water changes. Thank you very much for any input.

 

Looks like a type of coralline. Keep your Mg above 1280 and you should get the purple coralline.

 

how to get mg above 1280?