@CarlD covered the basics of proper fence design. Please consider using a professional installer. I had a wrought-iron fence installed around my pool during construction and the PB's subcontractor did a great job. It did not add a huge amount to the overall build cost and it's solid workmanship.

Also consider the following options as well -

- ADT alarm system so all external doors from home to pool are alarmed. Most systems can be programmed to give off an audible chirp anytime someone opens a window or door.

- Pool-code deadbolts. All my doors have pool-code DBs which is just a fancy way of saying the deadbolts are hung 30" below the top of the door frame. Impossible for any child under 9 years old or so to open the DB.

- Swim lessons for all kids and Infant Swim Rescue (ISR) training if applicable. I have personally witnessed an 18 month old baby let go in deep water, flip herself on her back and kick-swim to the coping....totally amazing!!

- Red Cross CPR training and rescue kit. Having at least one adult in the house that knows how to resuscitate a child can literally mean the difference between life and death.

And the simplest, no cost solution - never, ever under any circumstances let your children use the pool without an adult present AND poolside at all times.