Leaves turning black

The leaves on my short rider plant are getting black spots in the middle and around the edges. The are also curling under a little bit now. Its about three weeks old, in an aerogarden classic with a bubble stone in the reservoir. I'm using grown, bloom, and micro nutes from advances nutrients which i added 1.7 ml of each last Thursday. Any idea what could be going on and how to fix it? It's a little hard to see in the pictures

Looks a bit more purple then black. What are your temps like?

Around 78-80

I moved a fan to blow right on the lights. They may have been getting the plant itself a little too warm. I'll see what that does to help