Uncle Ben did a study on ST... He found it helped in early root production, and that’s about all… I use it mixed in my spray bottle when I spray the clones soil when watering, and when I am re-planting clones…After plants were complete, the ST plants differences after initial root production was nil… So, I only use it in my veg room at the start of plants…Uncle Ben did the test, and that’s good enuff for me…