blumat bottle cap adapter - 3 pack blumat easily convert a used plastic bottle to a blumat supply source. also great for backpacking water bottles, water purification, and many other uses. this works really well for hanging plants - both inside and outside. just attach the plastic bottle to the hanger and put the blumat in the soil. you can cut the bottom off the plastic bottle (you can use these cut off bottoms to make plant holders that keep wooden shelves from getting rings) and fill them from the top. if you prefer to keep the bottle intact, the water will last longer and you don't have to worry about insects getting in it but it's harder to fill. if you use the auto-stop version of this bottle cap though (ig15525), you can more easily move the bottle to fill and put back without spilling the water all over. this uses the thread type common on most one liter plastic bottles - not the same as 3/4" hose thread.