I read online that Super Thrive contains 0.09% vitamin B1 (Thiamine) and .048% 1-Napthyl acetic acid (a plant hormone). I'm sure you could find B1 or Thiamine at the Grocery but I'm not sure if you could find the plant hormone at a garden center or not. It is probably just easier to use Super Thrive.
I have been collecting, studying and selling hoyas for about 10 years. This Cubit is about growing hoyas, and about the hoyas I have to sell. I welcome any and all hoya lovers, whether you want to buy or not. Hooked on Hoyas is another great Hoya sight