Imagine a sixteen by thirty two foot, home residential swimming pool with a family of four and their five friends in the pool of approximately twenty thousand gallons. Then imagine them all getting out and entering a five hundred gallon hot tub with heated water. You have the same amount of people and wastes in forty times less the amount of water.
When using a hot tub there are guidelines that should be observed to protect your health and safety. Due to the nature of the high temperature of the water, small area of vessel, lesser depth and the increased velocity of water and air the spa is much more demanding.
Water chemistry and sanitizer levels are more easily changed with the smaller volume of water in relation to the bodies entering the spa water. Sanitizers not only dissipate quicker in the warmer water but also have a larger demand due to the sweat and urine introduced. The pH can change with the introduction of air and bodies as well. This pH change can also have an effect on the rate of sanitizing kill time. A swimming pool generally requires lower sanitizer levels as sanitizer can be replaced in the normal turnover cycle. Also, the dilution of wastes in the larger amount of water along with cooler temperatures does not allow bacteria growth as quickly as a heated spa. However, if the pool is heated you will see an increase in the demand of sanitizer as well.
Filtration is a crucial part in water clarity and removal of wastes in both the spa and pool. Spas require a turnover of approximately once every thirty minutes as opposed to a commercial pool of one turnover every four hours. To accomplish the need for better filtration it is recommended to use a cartridge filter on a spa. Many commercial swimming pools use sand filters although depending on the facility this is becoming a thing of the past due to energy concerns and the quest for better water clarity. The cartridge filter allows a finer micron to be filtered out with one turnover. Also the square footage on a cartridge filter is much greater than a sand filter can offer to accommodate the increase in dirt removal. Even with the offering of glass media which would prevent the clay formation of sand in hot water, the square footage and large micron removal makes a sand filter unsuitable for spas.
Spas can build total dissolved solids quicker than a swimming pool. A spa should be drained and thoroughly cleaned often. This includes the filter to be chemically cleaned. Total dissolved solids can inhibit the way sanitizers work in the spa and also cause cloudy water. Swimming pools are rarely drained and can be diluted to help compensate for an increase of dissolved solids. Also a swimming pool can change the type of sanitizer being used to slow down the increase of solids.
Both swimming pools and hot tubs alike have the same need for submerged suction safety. Neither should be allowed to operate with a drain cover missing or broken. Inspection for entrapment is equally important.
With the hot water of the spa it is also important that the user’s health be taken into account. People with heart problem history, users of prescription drugs and people with high blood pressure need to consult with their doctor before using. It is not recommended for pregnant women or children to use hot water spas. Spas can be highly therapeutic for others. However, swimming is recommended for all people. It is one of the best forms of exercise and enjoyment for a wide range of people.