Kelp extract for seedlings w/ first true leaves?
I have many vegetable seedlings coming up with their first set of true leaves and was wondering if it would be a good idea to water them with a seaweed extract (in my case kelp extract that has been diluted at about 2 tablespoons of the dried kelp to a gallon of water). I don't want to burn the roots by fertilizing too early, but if this would be a good boost to get them on their way to a productive spring, I am all in for kelp!
The seedlings are varieties of tomatoes, peppers, and herbs primarily that are growing indoors under lights.
If the kelp water is ok, what would be an advisable schedule for frequency of substituting the kelp-water for pure water?
Many thanks in advance for your thoughts and advice.