Algea or somthing??

[EXVISOR13]

Hi all ,I at one time was doing corals but deecided to go back to just a fish with live rock tank
Anyway I had this thick beautiful algea growing on the tank-filters and etc (green in color)
Since I stoped running the lights as mush and allowed my ph to drop its turned purple/brown ans is bubbled up and falling off like pealing paint
is this normal???
I have been taking it off little at a time, because I dont want to make to much of a mess, I have been netting what I can
also under it is still some green algea, not as nice as what I had though

 

[melosu58]

Lights were helping to maintain it and if you`re not running as much as before that could contribute to it. Maybe someone else can help

 

[EXVISOR13]

I was running them for 12 hours a day now running for about 8.5
never seen anything like this, like I said looks like bubbled pealing paint