Dry spots on Leaves

I would say it could be some transplant issues. Maybe the roots got a bit too dry or the new medium you planted it in is a bit different then the one it was used to so it burned a bit. Reusing old medium from a previous grow could have a lot of leftover fertilizers "and other things" in it unless you washed it out. It should grow out of this no problems asumeing the medium is not fully loaded with salts. I would water them a bit from the surface level to help keep that upper level moist so if the roots go exploring they are not met with dryness. Monitor the res for a spike in ec. if you see it. swap it out with clean water. Also next time flush your old medium and let it cook or mature in a big black garbage bag in the sun for 2 weeks or so. turning it every other day. This helps "pasteurize" it in a way. in quotes as its not true pasteurization but resembles its.

Hello! It looks to me like your seedlings were exposed to some extreme temperatures or dry conditions and possibly started sacrificing the lower leaves to survive. A laser thermometer is kinda nice for checking the leaf temperatures. If your environment is 84 degrees it is likely warmer on the leaf surface under the light... I saw that you mentioned on your diary about getting an AC unit to help control your temps. So hopefully your troubles are solved. It would still be good to double-check things like water ph, EC, and light ppfd just to make sure you didn't do something else to incite the plant to dry out.

Hello mate, the spots seem like if the water falls on the leaves the light burn them, except for this i shouldn't know what could be. Control the range of pH solution stay between 6.0-6.2 in the early veg phase and the amount of water you give them. Good luck and happy journey!

hey! Do you check the PH and EC of the nutrient solution? It looks somehow familiar. Maybe too much nutrients or an improper PH level. What type of lights are you using and what is the distance from the plants?