pea gravel
 

I opted not to set my fence post in concrete because I'll be replacing it in a 3 or 4 years when I can afford a nice cedar one. I have a pool so a fence has to be there. Anyway, I was told to just set them in pea gravel so I've been doing that using the beige stuff that I had left over from when I moved in. I think it's called shore gravel. I was tamping down the 4th post and realized that the post could possibly shift because the pea gravel is smooth and round. The post are tight but should I be using 3/8" bluestone instead of shore stone??

I would say gravel under the post then just packed dirt around the sides. Concrete is not necessary, even for your permanent post. Ever see a telephone pole set in concrete?