Urea?

[Phal grower]

Hi. I have been reading here and there on the forum that orchids can't utilize urea based nitrogen. I have been using miracle grow orchid food brand fertilizer and noticed that most of the nitrogen comes from urea. I was just wanting some feedback on this subject. What do you use for your plants? Is there anything readily available at the big box stores thats any good? I got mine fertilizer from wal-mart and figured that since it was for orchids it must be ok, now I'm not so sure. I've also read that if you plant in bark that you should use a 30-10-10 ratio. Is this true? Thanks everyone.