Scott's Very Simple Chemical Balancing Act

Remember: When servicing your hot tub, the heater is the first thing to turn off and the last thing to turn back on. This applies to electric or gas heaters. Turn off the heater 15 minutes before shutting down the pump. This allows the heater to cool down before the flow of water is stopped. On start-up, run the pump for 15 minutes before turning on the heater thermostat. This will ensure that the heater is full of water and will not inadvertently dry-fire.

1) The following procedure can be performed any time you wish to disinfect your hot tub, spa or whirlpool bath. Let's assume you have already drained the tub. If necessary wipe it down with a wet towel. A mild cleaner like Fantastik (TM), 409 (TM) or even regular dishwashing liquid may be used to clean the surface prior to refilling. They all cut through oily deposits. (Hint: A wet/dry shop vac makes the job a lot easier. Just be careful using electricity around water! Only plug tools into a Ground Fault Circuit Interrupter or GFCI protected electrical outlet.)

2) After refilling the hot tub with fresh water, add 1/2 cup to one full cup of liquid bleach. Now turn on the jets for a few minutes to clean out the pipes. Turn on the blower too if it has one. If the spa is really dirty, you may want to drain it again and repeat this process. [Sometimes when a spa sits unused for a few months, black stuff will blow out of the pipes upon initial start up. We believe this is due to mildew that forms inside the pipes, which often hold water, after the tub is drained and turned off. Repeated chlorine treatments will eventually kill and strip the mildew from inside the pipes.] While the spa is being disinfected, inspect and clean the filter also. A paper cartridge filter needs to look crisp and white, otherwise replace it. For sand or D.E. filters, refer to our filtration lesson in the pool section. (Hint: Be careful using liquid bleach. It is a dangerous chemical with toxic fumes. Drain chlorinated water only into closed sewer systems. Leave the spa cover off until the fumes dissipate. If indoors, turn on a vent fan. Do not enter the hot tub until the chlorine level in the water falls to a normal 3.0 ppm as indicated on your test kit.

3) To maintain a residual of disinfectant in the spa on a daily basis, use a small bromine feeder that floats or hangs in the water. Why are we switching to bromine? Bromine works at a higher temperature than chlorine. When the heat is turned up, the chlorine molecules will break down, but the bromine will remain. Put only two or three bromine tablets in the feeder to dissolve slowly over a week or two. It's easy to over disinfect a spa, so test the water daily with dip strips or drops. Adjust the feeder as necessary to achieve a steady reading of 2.0 ppm - 3.0 ppm. If the bromine level gets too high, take the feeder out until the readings return to normal. Too much bromine can damage your cover and damage your body. Once you get the bromine stable, test the water two or three times a week. (Hint: Try using convenient dip strips to check your water chemistry. Although they are not as accurate as drop type test kits, they are much easier to use. So you'll be more likely to test, and that's good.)

4) Let's talk now about the pH. With the exception of newly plastered gunite hot tubs, or areas where the fresh fill water is alkaline, hot tubs almost never have a high pH (meaning an alkaline or base reading of 7.8 or greater). The ideal pH of a hot tub is 7.4 - 7.6, so our job is mainly to raise the pH when it gets too low (i.e., acidic or corrosive). Any pH reading below 7.0 is corrosive and must be corrected using regular Arm & Hammer (TM) baking soda. No more than one level teaspoon should be added in a 30 minute period. We don't want to add too much and have to go back the other direction. Once you get the pH right, check it every time you check the bromine. Be aware that the chemical balance can change quickly in a spa, especially when it's used a lot. Four people in a hot tub is like having 50 people in a swimming pool. (Hint: Record your chemical readings on a calendar to see trends over time. This puts you in control by knowing how long it takes your readings to change.)

5) That's it for the chemicals! Now here's the trick to making this all so simple. Since water is much cheaper than chemicals, whenever there is a problem we are simply going to drain and refill the hot tub. In other words, think of your spa as a large bath tub instead of a small swimming pool. With as much water as a pool holds, we have no choice except to treat the water. But a hot tub can be drained and refilled in a matter of minutes. So if the water becomes cloudy or foamy, drain and refill the spa. Sure you could buy clarifier and de-foamer, but that taxes your filter. Just dump the water and start over again. If the water has an odd color or smell, don't put in dye or perfume, drain and refill the tub. After a big party, drain it. In short, a hot tub that gets used often, should be drained often. Keep in mind two things: a) your body soaks up the chemicals you use to treat your water, so keep it simple; b) just because there are googobs of chemicals available at your local spa store, does not mean you need to put them all in your spa.  (Hint:  A medium sized submersible pump that is rated at 1200 gallons per hour is the ideal way to drain a hot tub in about 30 minutes. Don't forget the GFCI outlet.)

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