Excessive nitrogen can also cause drooping that looks a lot like it needs water, but I don't know anything about the contents of the stuff you are using. If you soaked it until water came out the bottom of the container and you still haven't seen an improvement 8 hours later, then my earlier assumption is obviously wrong. They perk back up quickly. The salinity of nutrients is usually what burns the plants...at least this is the reason why overfed plants look thirsty as explained to me years ago. Might be urban legend, but I know that the "thirsty" look is one symptom of it.