Well, a couple of things. I haven't done the superthrive soak, but 1/4 tsp in a quart sounds pretty heavy duty as you're only suppose to use one drop per gallon. But if your method seems to work fine, then stick with it.
If you're plants are growing and turning yellow, I doubt if it's the superthrive but instead the nutes or lack of, that is the problem. MG has quite a bit to it, but it is also hot stuff. If I were you I'd change my fert use to something that a grow shop sells, even though it's more expensive. You could get an 8 ounce bottle of Dynagrow 7-9-5 and just follow the direction on the back. There are many too choose from; too many really. The powder ferts work good too, like happy frog or whitney farms. One cup of fert in a 5 gallon bucket will do. It sounds like you primarily have a fert problem so trying something else might be a good idea. Pics next time would be good. Composted manure might not be the best thing. Foxfarm or Roots or Promix or other decent grade of potting soil. It might be too late to fix your problem now so try taking cuttings and growing those and see what happens.
polishpollack Reviewed by polishpollack on . Superthrive seed soaking? I know not everyone agrees with pre-soaking seeds, but... for those who do, has anyone ever encountered an issue with soaking in Superthrive? I have a struggling bunch of seedlings, and I'm running through every possible cause of their dilemma. The only think I did drastically different this time was soaking in Superthrive solution (1/4 tsp/qt). They grew fine for about 2 weeks, and right about the time they should have been hitting veg and growing more quickly, they slowed down and the Rating: 5