spa chemistry Tag

Hot Tub Chemistry 101

From Swim University

If you are a hot tub owner, you have realized by now that a hot tub is a much different animal than a typical swimming pool.  The super heated water along with the smaller gallonage makes for a cauldron of bacteria, and makes it difficult to keep chemistry in balance.  Where else would you turn to for a basic lesson in Hot Tub Chemistry other than Swim University?  This post from Matt Giovanisci provides a blog post called Hot Tub Chemistry 101, which is indeed a great primer on hot tubs and chemistry for the DIY'er.

Here is an excerpt from the post:

from aquamagazine.com

Once any hot tub has been filled, an imaginary clock begins ticking, counting down to the day when the water will have to be replaced.

It's a costly but necessary process — costly due to the expense of sewering the old water and buying new, heating it to a user-friendly temperature and filling it with sanitizer and (in some cases) appropriate supplements. And then there is the cost of labor.

It's necessary because spa water contains more than just water. It's a high-performance solvent for a diverse set of compounds — some of these enter the spa in the sourcewater, others are added intentionally in water care products and still others unintentionally when the human body slides below the surface and begins to release dead skin, sweat and other greasy substances into the surrounding medium.

Over time the soup becomes imperceptibly thicker. This occurs partly due to evaporation as individual H2O molecules become airborne, leaving impurities behind in an ever more concentrated solution. But the primary cause is that over time, more and more bathers leave behind their wastes, and more chemicals are added to maintain pH, ORP, etc., and these simply build up.

At some point, water quality becomes difficult to manage. Its chemistry becomes unresponsive — sort of like driving a vegetable truck. Specific problems crop up, letting you know it's time to drain.

Several Reasons Why Your Hot Tub Is NOT Just a Tiny Swimming Pool

by Terry Arko via swimuniversity.com

Many who buy a hot tub often do so with a misconception that caring for a small hot tub will be easier and involve less chemical use and time than a swimming pool would. Those who have cared for spas/ hot tubs know that nothing is farther from the truth. These individuals have discovered that spas and hot tubs aren't just tiny swimming pools.

The Difference Between Pools and Hot Tubs

In fact a hot tub is much more than just a tiny swimming pool. There are many differences between a pool and hot tub and these differences call for a different and more strategic plan for care. Listed below are some of the major differences between hot tubs and pools.

Temperature – Most pools max temp 80° Spas/Hot tubs 92° to 104°

Higher evaporation rate – leads to more scale and increased calcium levels

Air jets and blowers cause quicker chemical reduction

Water balance – smaller body of water means greater effect on pH, total alkalinity, calcium hardness and TDS from added chemicals

Bather load ratio – 3 people in average spa/hot tub = 300 in a backyard swimming pool