Something useful I picked up. When mixing STS for making fem seeds, if you are using the sodium thiosulfate pentahydrate instead of the anhydrous form multiply the weight of the anhydrous form by 0.64 to get the weight of the pentahydrate needed.
Example: The formula calls for 1.25 grams of anhydrous sodium thiosulfate, multiply 1.25 times 0.64 to give you 0.8 grams of the pentahydrate needed. This is useful because most STS formulas I see are written for the anhydrous form but the pentahydrate is easier to get and is much cheaper than the anhydrous form. Hope this helps someone.
