Hi Kerry,
Start off with 1/2 teaspoon per gallon of water of HVH Specialblend. How much you can use depends partly on how you water. If the pots drain into a saucer and the excess is poured off you can use more fertilizer but if everything that gets poured into the pot stays in the pot, or is drawn back into the pot from the saucer as the pot dries out, then you have to be more careful. 1/2 teaspoon is a very low dose and won't hurt them at all. If they are 6 months old and have not been fertilized they need to be. You don't want them to take several years to reach first bloom, but for them to bloom next summer they need to be well nourished and eventually get some direct sunlight.
Thanks Charlie.
I was wondering why some of my seedlings looked soooo small. When I transplanted them they where competing for space

The bigger seedlings had nice healthy roots while the smaller ones looked like they where still younger. They should be happy now.