From this page you can find all awesome stuff that you can create with FIRE HYDRANT. This item belongs to bouncing category. Plant it and come back tomorrow, unless you want to spent ridiculous amount of spray. Is this farmable? Good leveling up material if the answer is yes. How many times you need to hit it? Head to the wiki for more info: fire hydrant By default you should get at least 1 seed back. Profiting with this might be questionable. Will you get enough blocks to build something? You just have to find out yourself.