Buying fertilizer to apply calcium and potassium to the soil is silly. Dried egg shells, banana skins and citrus skins have everything you need. Grind and apply to your garden and plants for a slow release calcium + potassium fertilizer. Add the DIY Calcium+Potassium Fertilizer mix when transplanting or sowing new plants. Recycle that stuff. Don’t throw it away. Save your cash. Help the environment and stick it to the parasites who sell us things we do not need. Permaculture is the Way!