Unknown Fertilizer

If you want, but if you already have enough K and S in your setup no point. Maybe give it to some of the outdoor plants? Looks to be a acid base reaction. IDK their claim it will add 20% to yield is far fetched. Prob just a basic product you don't need and they overcharge for. https://grow-pro.es/producto/pro-max/ Also this from the web: Is potassium oxide soluble in water? It is also highly soluble in water and forms an alkaline solution when dissolved. It is extremely reactive and reacts with water to form potassium hydroxide, a very strong alkali. Is sulphur trioxide soluble in water? sulphur trioxide is insoluble in water due to its covalent nature. Hint: Contact process is the industrial method of producing sulphuric acid. It is also called lead-chamber process. Sulphur dioxide and oxygen combines to form sulphur trioxide, which reacts with water to form sulphuric acid.