Laterite beneath sand?

I'm currently (still) gathering materials to set up my new 55gal. I'm going to give a planted aquarium w/ sand substrate a try. I've been reading that the plants need a base layer of laterite beneath the sand to thrive.

My concern is that when I have to stir the stand to prevent bacterial pockets, that I will stir up the laterite? Is this reason for concern?

If it is recommended to use a base layer of laterite? How deep should the layer be?

Thanks for your help, everyone here is so helpful.

Trumpy

Thanks Roan, will do.