Are Hot Tub and Pool Chemicals the Same?

Are Hot Tub and Pool Chemicals the Same?

If you’re one of the lucky ones, you might own both a swimming pool and a hot tub. That said, being a proud owner of both, you’ll know that you need to keep an eye on the water chemistry and make sure the levels of pH, total alkalinity, calcium hardness and more are kept in balance. Failure to do so can result in water that can damage components and make it very uncomfortable for bathers. If you’ve ever compared the chemicals you add to your pool with the ones you add to your hot tub, you might have noticed that they contain virtually the same ingredients. But are hot and pool chemicals the same? The fact is that they are not. In this article, we’ll go over the differences between the two and explain why you shouldn’t mix and match these chemical additives.

Chemical Composition

Although swimming pool and hot tub chemicals may share similar ingredients, if you look closely, you’ll realize the concentrations of these active ingredients are quite different. There are several reasons for this that we’ll go into later. But the bottom line is that switching between swimming pool and hot tub chemicals can alter the water chemistry in ways you don’t anticipate. You could end up seriously damaging the components of your hot tub or swimming pool while ending up with water that harbours dangerous bacteria. The different chemical compositions of hot tubs and swimming pool chemicals make them unsuitable for substitution.

Water Volume

Unless you have an extraordinarily large hot tub and an extremely small swimming pool, your swimming pool will hold much more water than your hot tub. Because of this large volume of water, the swimming pool chemicals you use will need to be much more concentrated than chemicals you use for your hot tub. If you try to use the swimming pool chemicals in your hot tub, you’ll find the water chemistry levels will go through erratic swings that are hard to control. On the contrary, if you add hot tub chemicals to the large volume of water in your swimming pool, you may end up using all your chemicals and still see no change in chemistry levels.

Water Temperature

Water temperature plays a large role in how swimming pool and hot tub chemicals work. It’s obvious that hot tubs are much warmer than swimming pools. Most hot tubs run around 40 degrees centigrade, while swimming pools usually range between 25 and 30 degrees. Because the temperature of the water in a hot tub is much higher, chemical reactions will take place much more quickly and efficiently. By using highly concentrated swimming pool chemicals in a hot tub you may end up with chemical reactions that radically alter the water chemistry and make it hard to properly control. Conversely, hot tub chemicals used in a swimming pool won’t be able to fully react and create the proper water balance you’re looking for.

Water Jets

Although both your swimming pool and hot tub will have water jets, the ones found in your hot tub will be much more effective at stirring up the water. This is both due to the smaller volume of water found in a hot tub and the strength and number of water jets. This increased water circulation will cause added chemicals to react quicker and more vigorously. And if you’re using highly concentrated swimming pool chemicals in a hot tub, you’ll find your water chemistry quickly going out of balance.

Water Evaporation

The temperature, size and force of the water jets in a hot tub means that the relative amount of water that evaporates is much higher than in a swimming pool. This evaporation concentrates the chemical composition of the water. If you add highly concentrated swimming pool chemicals to the hot tub, the chemical balance will be quickly thrown out of equilibrium.