Purple/Maroon Leaves, Little-no growth [w/ Pics]

Under CFLS (12 inches away), in desert potting mix mixed with perlite. I had given them some MG a few weeks back then have been flushing it with distilled water every time I water it since. It has had this problem before flushing and it has not improved. Temps are no higher than 85 during the day and no lower than 75 at night so I have no reason to believe it's heat stress.

Is this a deficiency of some sort?

nute burn, look at the tips, causing P lockout, turning it purple. Plus the CFL lights need to be 1" away, not 12`inches.

that's not nute burn, that is lack of food. You need to feed them and he is right get your lights alot closer.... The purple color is from a lack of nitrogen and you can also see they are turning a pale yellow, another sign of the plant needing nitrogen and I'm also guessing that since you have been flushing them with distilled water that you might have other defs. You want to hit them with a good veg food