DO NOT USE UREA AS FERTILIZER! I used some I had received with a dwarf water lilly about 15 years ago and wiped out all non-plant life in my tank, including a beautiful plecostomos I had had for about 5 years. The ammonia or ammonium released is highly toxic in such a small environment. -Gerry Skau In Ann Arbor, Glad I'm Not In Lincoln or Omaha!