I know you didn't ask me but I thought a variety of answers would give you more choices, Carol. I water with the MSU formula (mine is for RO water) and some physan (to prevent rot) mixed in every other week. If the cymbidium leaf tips get brown I fertilize every three weeks since it is a sign of over-fertilization. I use a backback sprayer. I can only handle 2.5 gallons at a time so I usually fill it twice so it's not too heavy.
