How often to dust leo's crickets with and what to use

So, I recently got an adult male leopard gecko, and I was wondering how often I'm supposed to dust the crickets and what I'm supposed to dust them with. My plan is to feed him 5-8 crickets 3 times a week, and I'm going to dust the crickets with calcium w/out d3 the first 2 feedings and then use reptivite the 3rd feeding. I'm also keeping a small dish full of calcium w/out d3 in his terrarium at all times. Does that sound like a good plan? I've heard to use calcium w/ d3, but if I use reptivite do I have to use calcium w/ d3?

Thanks in advance!!!

I would use calcium + D3 for dusting on the days you don't use Reptivite. Calcium cannot be used by the gecko without D3, and unless you are providing UVB light for them to make their own D3, they need to obtain it from their diet.

You can still use calcium without D3 in the dish inside his cage.