This Guy Built His Own In-Ground Pool For $3000... With Step-by-step Instructions (and video)
Drill holes in the walls and install rebar for strength for every step.The empty space between the step and the wall, lay packed sand.
When preparing the floor of the pool, a layer of course sand was poured to get the ride height desired. Then rebar is laid in a patchwork design to make sure you have the maximum strength.
Install a 3 inch plastic pipe sleeve as a drain pipe near the pump house.
Next a 1 inch to 1.5 inch pvc pipe is routed from the jets on either side of the pool to the pump house as well as to the clean out for the sweep hose.