Affordable Hot Tub Repair

Find us on YelpText or Call: 619-342-5442Find us on Facebook

Contractor's License: 977562

A Hot Tub is not a Small Swimming Pool


Hot Tub Repair

Simple Hot Tub Chemistry

  1. Hot Tub Chemistry Fundamentals

  2. Why you can't treat a portable hot tub like a Swimming Pool

  3. Total Alkalinity & pH

  4. Sanitize & Oxidize

  5. Step-by-Step Hot Tub Chemistry Checklist with dosage tables

  6. Simple Hot Tub Chemistry Selector

  7. Hot Tub Chemical Damage

Hot Tub Water Conservation

Hot Tub Electrical Safety

If you have read the Hot Tub Chemistry Fundamentals page, you already know a covered hot tub is more like a sealed tank of water than an open swimming pool so it does not need a 'daily dose' of chemistry.

You should also be aware most of the instructions you'll find on hot tub water chemistry are borrowed from the swimming pool industry and simply don't work in a portable hot tub. That's why you can follow these instructions to the letter and still get bad results.

Plastic vs. Plaster

A fundamental difference between your hot tub and a swimming pool is construction. A swimming pool is usually made of concrete and plaster and both these materials are very porous and very reactive to water chemstry. That means the pool surface is actually part of the ongoing chemical reaction.

In fact, water chemistry in a brand new pool must be adjusted to accomodate the changing environment as the concrete completely hardens over the course of several months..

If the water in a swimming pool is to acidic, it will slowly dissolve the plaster finish and even start eating into the concrete structure. If the water is too alkaline, it will leave crusty scale deposits that must be acid washed and sometimes sand blasted to remove.

Managing paramaters such as pH, Alkalinity and Hardness is critical to prevent long-term damage to the surface and structure of a swimming pool.

Draining a swimming pool to refinish the surface can cost thousands of dollars.

Your hot tub is made almost entirely of inert plastic. The only metal component in contact with the water is a heater designed specifically for the harsh environment of hot tub chemistry.

This means your hot tub is not easily damaged by imbalances that would otherwise destroy the surface of a swimming pool.

You are much more likely to damage a portable hot tub by overdosing sanitizer
than by neglecting water balance such as ph, Alkalinity or Hardness.

Hot vs. Cold

If you have ever had food poisoning, you probably know bacteria can thrive in food if you don't store it properly. Bacteria reproduces prolificly between 40°F and 140°F.

Outdoor pools in San Diego rarely get above 80°F even when heated. The cooler water in a swimming pool helps to inhibit bacterial growth.

Most portable hot tubs are kept at 100°F or higher which is smack in the middle of the 'Danger Zone' and a sweet spot for bacterial reproduction.

The higher temperature in a hot tub also means more perspiration and body oil and the jets scrub off more dead skin and loose hair.

This organic waste can become a never ending food source for bacteria and everything on this buffet line is maintained at the same temperature as a person with a fever.

All this means a hot tub can go from a sanitary soak to an itchy rash a lot faster than a swimming pool so the primary purpose of hot tub chemistry is always sanitation first and foremost.

Hot water promotes bacterial growth;
Check sanitizer level before every soak

Gallon vs. Gallon

Size, or more accurately volume, absolutely matters when it comes to hot tub chemistry. A typical residential swimming pool holds around 15,000 gallons of water. A typical portable hot tub only holds around 400 gallons of water.

All the extra water in a swimming pool can absorb and dilute a lot more chemistry and contamination. This means a pool is much more tolerant of chemical overdose and has a bigger chemical reserve that prevents dramatic changes in water quality.

Easier to Overdose
If you need to increase Chlorine in a swimming pool by 3.0 ppm you mght have to add 10 Ounces of Sodium Dichlor.

To achieve the same 3.0 parts-per-million in a hot tub, you only need to add 0.3 Ounces. This is why it's so easy to overdose a hot tub.

Less Chlorine Reserve
When the swimming pool above becomes contaminated, there are 10 Ounces of Chlorine in the water available to clean it up.

When the hot tub becomes contaminated there is only 0.3 Ounces of Chlorine available. With less of a reserve, the Chlorine in a hot tub can disappear a lot faster than in a swimming pool.

Higher Bather Load
The smaller volume of water also means the bather load is more concentrated. Two people sitting in a 400 gallon hot tub are the same bather load as 75 people in a typical swimming pool.

The smaller volume of water in a portable hot tub makes it easier to overdose and harder to keep sanitary at the same time.

©Affordable Hot Tub Repair, 2014