Purple Hulk Auto under the CREE

This plant is so odd ... theree weeks ago it stopped really growing at all. I did use some Flower Fuel for a few waterings and wonder if that may have had something to do with it. Last two were plain PH water and it seems like all of sudden she’s growing again and turning purple. I do love be Purple color it’s comic in pretty good now as my nights here on tne flower room get Colder.