I had bought Schultz's Orchid Plant Food last night so I could use it my weekly watering this weekend. The strength is 15-5-5 however I've seen people using different ratios (hope this is making sense). I checked the packaging for contents of Urea as well but it doesn't state that there is urea in in there. Does anyone have experience using this product and if it is good to use? It states it is good for all varieties of orchids.