Without lighting, using your pool after dusk is difficult. It's easy to add subsurface lighting to your pool if you have the electrical lines. This will cost around $900. Upgrades like dimmable or color changing lights can be made.
While the application of polymers is not a typical DIY job, epoxies can be applied much more easily. Depending on the size of your pool, costs can range from $1,500 to $15,000 for epoxy and up to $15,000 for polymers.
There are three types, vinyl, fiberglass, and concrete, of inground pools: ones with vinyl lines, those with fiberglass liners, and ones made from concrete.