I routinely use about 1tbsp/gallon for my house plants. Outside plants get none but the occasional rains do keep them happy. I have a friend who uses small amounts of sulfuric acid to do the same Sent from my 📱 _______________________________________________ pbs mailing list pbs@lists.pacificbulbsociety.net http://lists.pacificbulbsociety.net/cgi-bin/… Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net>