I'm pretty young (turned 18 last summer) so when I walk into a hydroponics shop the people behind the counter normally assume I'm growing pot. At least that's how it was for me. Without saying anything about what I was growing the guy knew what ph I would be looking for and was recommending me foliar sprays to "cut down my veg time".

It's probably not like that EVERYWHERE, but.. people aren't dumb. Most of them are gonna know and probably wont really care since you're giving them business.