Stunted 2 week old seedlings, purple spots?

Hey there everyone, 2 weeks into my first grow, i guess ill break down the setup:

Location: there in a small room, door open with an open window like 20 feet away. in about a week ill have access to a much better room and i can get a proper setup in place

medium: islands finest organic potting mix, ph balanced, with perlite, peat moss and and some fish nutrients or so sayth the bag

seeds: 80/20 indica/sativa, bc mango

temps: 73 -85

The lighting has evolved since i started for better or worse i have no idea. I started off with a 400 watt hps and eventually because of heat and streching, i switched to 5- 26 watt 6500 k, a t5 and one soft white. at first they were within 1 - 2 inches of the leaves but they looked stressed and are now at 5-8 inches away

They started to look better for a while but now i have one plant with purple spots on the leaves, and my pilljar plant is all droopy, growth has slowed to a crawl.
They seem to have good root systems i can see roots in the drainage holes. Ive been watering every 2-3 days when the pots feel light to me but i guess this is an aquiered skill i might have been going a bit light on the water but im scared to overwater and stunt em more I guess my question is since its been 2 weeks should i give them an REALLY weak feed on the next watering? will this help em take off of just burn em terribly?
Could the slow growth be caused by improper airflow?, any other tips, comments would be appreciated.

Thanks

at 2-4 weeks most growers i have heard start using half strength nutes on the plants. Personally i do wait a month... your other seedlings look great... one reason that might be causing the droopy leaves is overwatering. As for the purple spots im no expert so i would wait for someone else to help as well.

hmm ya i think ill hold off on the nutes, im just hoping the purple spots arn't the sign of some deficiency, dont wanna deprive my babies

Lungz said:

hmm ya i think ill hold off on the nutes, im just hoping the purple spots arn't the sign of some deficiency, dont wanna deprive my babies

Click to expand...

This could be one reason ... maybe.

a)

Leaves are dark green or red/purple. Stems and petioles may have purple & red on them. Leaves may turn yellow or curl under. Leaf may drop easily. Growth may be slow and leaves may be small. >> Phosphorous (P) deficiency.