An easy way to know whether your sand filter has enough sand is to check how full the filter is and what the sand looks and feels like. The filter container should be two-thirds to three-quarters full of sand. Look for interior marks indicating the ideal sand level. If you put your hand into the sand, it should flow through your fingers without clumping. The filter pressure gauge is also an easy indicator—the right amount of sand leads to normal pressure, while too much or too little sand can cause high or low pressure.

An aboveground pool should be level within 1 inch—and it starts to become unsafe after a couple of inches. Any slope will lead to an uneven distribution of water, which will put pressure on your pool’s structure, wearing down the pool liner. In certain cases, it could cause your pool to collapse. Even if you’re within a safe window, you may still notice that the water level is uneven.

In-ground pools lose water naturally due to wind, heat, and humidity. They also lose water from the kiddos' cannonball competitions. But be mindful of the water level. If it drops too low and the pump draws in air instead of water, it will likely be damaged and require repair or replacement.

If you wait until fall or winter, you might see sales on pools and pool materials, enabling you to save a good amount on this home improvement project. Sometimes pool servicing companies try to make space for next year’s inventory, or the materials are cheaper when fewer construction projects happen during colder months.