HAPPY FROG - Nutrient Level for Seedlings??

Hello
I have been asked when seedlings should start receiving nutrients?
They're growing in HAPPY FROG,
they're very small for the few weeks they've been growing.
AND they are developing RED SPOTS on the leaves and stems.
The grower is having difficulty uploading photo's but will keep trying.

The grower has only a very basic grow set up.

He has an 150w HPS and I advised him to keep it about 4ft above the canopy
(I keep my 600w MH 6ft above my propagator when I can't use CFL's).

Anyone who can offer suggestions to help will be doing this kid a great favour.
Most of us have had times when we had $80 grow rooms and $80,000 grow dreams.
So, come on. throw a dog a bone and help turn this guy into a successful marijuana cultivator.

Happy New Year.

Without pictures it's hard to say for sure, but from what you described, it sounds like a Cal/Mag deficiency.
You can find bottles of Cal/Mag at your local hydroponic shop, just follow the directions on the bottle, and you should be set.
Remember though, the plants will take time to recover, so don't expect them to turn around overnight.
Good luck.

It definitely isn't the Happy Frog...My guess would be the HPS lighting. Seedlings don't respond well to red wavelengths of light, even well established plants in vegetation prefer a spectrum of light closer to the green/blue end. That would be my guess, though. Good luck!!