I like using Peters Excel. I havent been able to locate much of it. I found Pro Horticulture in Ontario sells 25 lb bags with shipping to the US for 63 dollars. Not bad considering I been paying 7 dollars a lb for it hey?
Most others I have found only sell wholesale to growers and I dont QUALIFY yet as a professional bec I havent killed a 1000 orchids yet
I use the peters on everything around the house. I think the weeds even love it.
it is 15 5 15 7 2 on the numbers if you are interested. It Has calcium and magnesium in it so you dont have to play with oyster shell and the epsom salts.
I'm trying to get interested in this again and with 25lbs of fertilizer I get to feed lots of orchid mouths...
its a lot of it for the casual grower indeed but if you store it properly it should last. If it gets too hot n humid its turns to blue mud. got to keep it inside nice and cool.