11 day seedlings: Yellow leaves

This is the first time that I've done seedlings due to this being the first time that I haven't had access to clones. I guess I'll describe my problem, and what I did to solve it, and perhaps someone could tell me if my actions were shrewd.

I had 10 Jock Horrors under a cfl in a flood table. As I was perusing the internet for seedling TDS limits, I found contradictory information. One site said a weak solution at 300-500 PPM, and the other said 50-150. I decided to go with the former. Well... yesterday I noticed a few tips and sides were burning on the second leaf set, (plants are currently developing their third set) and because of how I had my CFLs setup about 12 inches from the plants, I immediately assumed that my issue was a lack of light.

So I disconnected my cfl, and I switched to my 1000W HID, but the problem continued to get worse within the next 10 hours. So next I assumed that my problem is N toxicity. My tds had risen to almost 500 (with tap water at 170) by the time I dilluted the nutes. Now I have a TDS reading of 320 which give me a nute PPM of around 150.

I understand that nute uptake is incredibly low until the proto-leafs wither. Does it sound like the change in my nute solution was drastic enough? Or should I empty the thing and switch to water? I really want to nip this problem before my youngsters suffer anymore.

Thanks,

HTT

I dont feed seedling any nutes until they are almost 3-4 weeks old. i also keep them under my T5's so the intense light would burn them. go back to your CFL's and get rid of the nutes.

Thanks for the speedy reply. I've read that seedlings can handle HID by the third leaf set. Is this not true?

At this early stage, less is always better. I'd use a minuscule amount of nutes if any for three weeks. and cool lighting. I'd also use purified water since they're not taking in much anyway. Go back to the CFL's. Some plants are very PH sensitive, the PH around my parts is 8+ out of the tap because it's all limestone around here I have to use PH down.

yes they HID is fine but they will use alot of water make sure you keep it far away and i would just use water with no nutes and foiler feed once every other day. make sure the lights are off or you will cause leaf damage i hope i was to any help =]

Your ppm's don't sound way off. In a flood table it sounds like you're running the right solution for rock wool in hydroton. My suggestions are to check your pH and make sure your values are consistent and perfect. Your water sounds like poor quality, so switching to filtered water is a definite yes. Hell, even a brita would help. Make sure you're letting that water sit 24 hours before adding anything also as the chlorides can bind with elements in your solution to create salts.

I keep my CFL bulbs MUCH closer. 12 inches is WAY too far. 6 inches at most for a very high wattage bulb. I keep my 27w bulbs within 1 inch. Keep them as close as you can by testing the heat casting with the back of your hand from the bulb. Where the heat stops is where the plant needs to be.