I would not feed any nutrients to your seedlings until they recover.
I would introduce a calcium and magnesium supplement containing calcium nitrate and magnesium nitrate Such as Botanicare's Cal-Mag Plus after 2 good weeks of vegetative growth from a seedling. Cal-Mag Plus and CaliMagic are synthetic calcium and magnesium supplements. If you are using a natural source of calcium and magnesium based calcium and magnesium supplement such as General Organics CaMg+ you can start to add at the start of vegetative growth. I use Botanicare's Cal-Mag Plus at 5 milliliters or 1 teaspoon per gallon as a calcium and magnesium supplement for the majority of my cannabis plants.
(Click on the photographs for direct links to the products)
I would introduce a calcium and magnesium supplement containing calcium nitrate and magnesium nitrate Such as Botanicare's Cal-Mag Plus after 2 good weeks of vegetative growth from a seedling. Cal-Mag Plus and CaliMagic are synthetic calcium and magnesium supplements. If you are using a natural source of calcium and magnesium based calcium and magnesium supplement such as General Organics CaMg+ you can start to add at the start of vegetative growth. I use Botanicare's Cal-Mag Plus at 5 milliliters or 1 teaspoon per gallon as a calcium and magnesium supplement for the majority of my cannabis plants.
(Click on the photographs for direct links to the products)