I use the hose-end liquid MG fairly regularly on my outside orchids, no issues so far for me. (Other than a little left-over white residue spotting the leaves that is easily cleaned off)

Good luck,

Bob

Likewise here. I use MG 20-20-20 at full strength when I think about it. During the summer could be once a week. You'll be fine with that, especially since orchids don't use much phosphorus.

Full strength once a month, half strength every 2 weeks is what's commonly recommended for orchids. You are in track.

Nick

Thanks everyone. I have used it once but didn't know about trying it again. I will now.