Those who have been around swimming pools and hot tubs for any length of time might eventually notice that the ingredients in the chemical additives used to balance the water chemistry might, at first glance, appear to be the same. This is despite the fact that they’re clearly labeled either hot tub chemicals or swimming pool chemicals. Are hot tub and pool chemicals the same? To clear up any confusion in this matter we’ve come up with an article that explains why it isn’t a good idea to interchangeably use hot tub and swimming pool chemicals.
Chemical Concentration Differences
As mentioned in the introduction, a quick look at the ingredient list on swimming pool and hot tub chemical packaging may make it seem like they are the same thing. Sanitizers contain chlorine, pH increasers contain soda ash, pH decreasers contain muriatic acid and so on. So, what’s the difference? The main difference between the two are the concentrations of the active ingredients. For several reasons, of which we’ll go into more detail below, swimming pool chemicals are much more highly concentrated than hot tub chemicals. And it’s for this reason why it’s a bad idea to try and mix up the two.
It doesn’t take a genius to realize that swimming pools typically hold much more water than hot tubs. And it’s because of this that swimming pool chemicals need to be much more highly concentrated than hot tub chemicals. If you tried to use hot tub chemicals in a swimming pool you would probably use up your entire supply before you saw any change in the water chemistry. Similarly, using highly concentrated swimming pool chemicals in the relatively small volume of water in a hot tub would cause wild swings in the measurements you were trying to take.
Another factor that affects chemical reactions is the temperature at which they take place. The higher the temperature, the faster and more robust the chemical reaction. With hot tubs typically running as high as 104 degrees Fahrenheit compared with swimming pools in the 70s and 80s, you can easily see that chemical reactions will be much more vigorous in a hot tub. This is one of the reasons that hot tub chemicals have lower concentrations of the main active ingredients. If you add highly concentrated swimming pool chemicals into the warmer waters of a hot tub, you may find your water chemistry levels quickly spiraling out of control.
Chemical reactions take place when particles collide. The faster that particles move mean the more collisions that take place and result in higher rates of chemical reactions. Water circulation increases the speed at which particles move around which encourages chemical reactions to take place. Because hot tubs have much stronger water jets in a much smaller volume of water, chemical reactions will naturally occur more frequently. By adding highly concentrated swimming pool chemicals into a hot tub you may end up with such vigorous chemical reactions that the water quickly becomes unbalanced and unmanageable.
Water evaporates from hot tubs much more quickly than it does from swimming pools. A lot of this has to do with the higher temperature and increased circulation of the hot tub water. As water evaporates, the concentration of chemicals left in the water increases. If you try adding highly concentrated swimming pool chemicals into water that already has a high concentration of chemicals, you may find your levels getting out of control.
To learn more about the chemicals needed for your hot tub, download a free hot tub buyer’s guide today.