A one gallon container is a tad large for a seedling. Works best to start smaller and work-up in size. Saves nutrients, ph adjusting liquids, and the plants seem to prefer a little root bondage.

Might want to raise the lights a half a foot (or more) till a tad stronger and able to handle the heat and light intensity. Seedlings won't benefit if fried, and your medium should stay moist longer. Deep watering with properly ph'ds water, let dry. If this means watering once or twice a day, then so be it. No way around it unless you crack seeds with CFL's or Fluorescents.

The chunky organics in your MG are a bitch for young roots to navigate. Might want to crumble it up better before adding seeds.

MG is notorious for being difficult for newbies, seedlings and clones. But as long as you don't jump the gun on additives and nutrients and stuff, they usually handle it fine. Raising the lights help them better handle the MG nutrient assault, too.

Some like to add some extra perlite to their MG after their first transplant to lighten the mix a tad. It helps, especially if not yet used to watering schedules and such.

Keeping temps more consistent helps seedlings remain strong. They don't like chills.

Ingoing ph is a tad high, but the buffers in the MG will handle that for a while. If narrowed down to a ph problem, you might need phDown or something similar to lower your ingoing water ph. Fresh potting mix should be fine for runoff for at least a month depending on what and how much buffering additive they've used.