it's good stuff if used properly. i use it and have for many years, both indoors and out. i am not saying it's the best, it isn't. it just works well for me...my pics are around here and marihemp to prove my words are true...

i use it at 1/3 to 1/2 strength of what the directions calls for and only apply it once every 10 days, at most. iow, for an indoor grow they only get ferts 2-3 times total before flowering...when i switch to "pure blend-pro". an outdoor grow can handle more so i jump it up to 1/2 strength every week.

now for your prob...i suggest starting a new batch of seeds immediately. seedlings don't take well to any fertilyzers for the 1st few weeks and their root system isn't developed enough to handle a good soaking. but don't give up on em...GENTLY flush with room temp water until soil runs clear. when it's clear, give em a dose of super-thrive or other stress reducing hormone solution then leave em be for a week (assuming they're in one gal minimum pots...much depends on the pot size as far as timing). the last thing ya want to do is disturb the roots. keep the fans running so the water in the soil can evaporate as quickly as possible and do not add more water until soil has dried to the point your plants are wilting a bit. if the soil gets too clumpy or hard, use a toothpick or similar to gently break it up a bit for good drainage and so air can get down to the roots (but not too much)...then begin your normal care for them.