Any number between 7.2 and 7.8 is an ideal pH for swimming pools or 80 to 120 ppm. Your pool testing kit should be able to measure both of these numbers. If your pool’s pH is below this range, the water is too acidic and can cause scaling and damage to pool equipment. If the water’s pH is above this range, it can decrease the effectiveness of necessary chemicals, like chlorine.

How often you should add water to your pool depends on how quickly the water evaporates. Keep an eye on your skimmer box, if you have one. Top up the water in your pool if you notice the water levels are lower than the bottom third of your skimmer. This helps prevent damage to your pump. 

Replace all the water in your pool every five to seven years, depending on how often you use your pool, the weather, and whether or not you close your pool for the winter.

In most states, it is a legal requirement to have a fence around your pool to protect both swimmers and pool owners. These laws can vary by state, city, and county, so you must research the specific regulations in your area before installation. The rules may also differ for inground versus above-ground pools, with inground pools typically requiring a full fence. Additionally, most homeowners' insurance providers will require a fence around a residential pool before providing coverage. As a general rule, it's always best to have a fence for everyone's safety.

With a regular pool, the water is contained by visible walls that are higher than the water level. An infinity pool has one or more walls that are right at the waterline so they're not truly visible. For an invisible look, the lower wall is often made of glass or clear acrylic. The water laps over the lower edge and into a catch basin below where it gets pumped back into the pool.