Leaf symptoms - what am I doing wrong?
I tried to read up as much as I could before starting, but my plants aren't doing very well, and I have not a clue which part went wrong. Please take a look at these leaves:
This is a collard seedling, one of the leaf started to get small yellow spots and the tip curled. I had other leaves that curled ended up drying and shrieveled up.
This is a Mustard Tokyo Bekana, I have serious trouble growing this type, NONE of them are doing well, their cotyledon dies as soon as the first true leaf emerge; then the true leaves go down hill whenever a new leaf emerge...
Here are some background information:
The growing medium is turface, akadama, perlite and peat; plus a bit of lime. I added vinegar to the water to adjust the PH to ~6.4. I began applying a weak solution of FP 9-3-6 as soon as the first true leaf appears. They were grown under two T5HO, placed within 3-4" from the tubes. Temperature is mostly around 75F.
Initially, I thought I over-watered as I watered everyday; and ended up with the top layer of the mix getting moldy. Now that I have corrected the problem by watering only twice a week, the mold is gone, but the leaves are still dying one after another. I have these lights on a timer, they come on at 6:30am and off at 7:00pm. I turn on a fan when I wake up in the morning, but there is still about an hour without it. Without the fan, temperature gets up to 91F. Can the one hour of 91F cause the leaves to curl and wilt?
Then I read about water PH; and found some information that says it is better to lower the PH to 5.0-6.0 for soiless mix; out of this range there will be nutrient lock out. Could my PH be off causing some nutrient lock out?
One last question, do you think I'll be better off pulling out the plants to start over again? I was thinking perhaps the roots were already hurt when I over-watered them at the start. Thanks.