Medicine Hat Residential Swimmer – Russel Koch


A solar cover has more than one purpose.  One reason for using a solar cover is to heat the water in your pool.  Depending on your pool location, with the sun, a solar cover can raise the temperature of your water 4 to 8 degrees in one day.  However, there are many factors to consider.  The depth of the water, the amount of sun the pool receives, and the outside temperature are all considerations.  As well, look at the length of time the cover is left on if the water is normally 82 degrees but the sun warms it to 86 degrees by 2 o’clock in the afternoon.  If this is the case, no mechanical energy is being used to heat your pool.  Note that if the pool is covered at night, the heat loss during the evening will be minimized.  At times, the pool may only lose a couple of degrees if it is covered at night.  In fact, it is not uncommon for an in-ground pool to maintain a temperature between 82 and 86 degrees without the use of a heater during a warm deteriorate.

Another purpose of a solar blanket is to minimize the evaporation of the pool water.  If the day is hot and windy, a pool may lose up to 3/4 of an inch of water in one day.  Even without the wind, water may be lost due to evaporation.   A simple test that will show how much evaporation occurs in one day is to take two empty ice cream pails outside.  Fill both with pool water, and set them on your swimming pool deck in direct sunlight.  Cover one pail with a green garbage bag, and leave the other one uncovered.  Check both pails in a day in order to check the water levels.  The covered pail should have more water as it would have had less evaporation.

The solar blanket also helps to keep dirt and debris out of the pool. When the wind blows, it carries dust in the air. When the wind passes over your pool the dust from the air will be extracted and ends up in your pool. Also if leaves fall in your pool, sometimes a cover will keep the leaf on top and the leaf stands a better chance of blowing off. During grasshopper season, keeping your cover on your pool helps to keep some of the grasshoppers out of your pool. If a grasshopper lands in your pool, he can’t jump out, but if he lands on your cover, he still has a chance to hop out of your pool.

Keeping your pool cover during the hot weather also helps to maintain your chlorine levels. One of the factors concerning chlorine and how it is diminished is direct sunlight. Two pools, side by side, with one beginning cover and the other pool left uncovered, will require different amounts of chlorine if all other variable are the same.


No, the sun will also deteriorate   your solar cover the longer that the cover is in direct sunlight, but  it is still cheaper to replace a cover than the cost of fuel, the time to clean, and the cost of water and chemicals.

Covering your pool makes sense, but at the same time you can’t enjoy your pool if it is always covered. So keep your pool covered when not it use, but lets remove the cover and enjoy the pool  as much as we can during the summer.  Have a great summer.