Hey, try 3/4" rigid for the underground, less depth always. 3/4" is my minimum UG feeds for any distance and even 2/3 wires, always makes life easier now and in the future. Bring the feed into the bottom of your box, and in the next hole in the box is my 3/4" rigid beat into the ground 5/6' for stability, very clean install, and some additional grounding help. I always use double boxes and deep. If you feel like it, back-up two single deep boxes, switch on back, outlet facing pool. Careful of the general use GFI rule though.Typically don't use GFI breakers due to cost, usually use a faceless next to general use GFI.