This is my setup, just finished germinating them, and i put them in the lava rock. 10 gallon bubbler tank, with 3 airstones and 3 pumps (MAYBE overkill, but can't have too many bubbles, right?) The HPS light is about 20 inches above the plants. Should it be higher, lower, or good there? I'm unsure of the wattage- got it from a friend, no UL or safety labels. Anything else that looks wrong that I can fix? (this is obviously low budget grow, but i did get my seeds from Attitude, so they're feminized)
What temperature is your HPS? Generally, seedlings and vegging plants like a bulb temperature in the 6500K-7000K range and most HPS are in the 2700-3500K range. I think I'd throw a couple of 6500K CFLs in there just to make sure they are getting enough blue. If your bulb is cool, the light can be right over the plants. Stick your hand under it...if it is uncomfortable for you, it will be hard on your darlings. Peace, Bak Alchisk