Are You Adding Too Much Hot Tub Sanitizer?

In most cases, excessive sanitizer will not permanently damage the operation of your hot tub, but it will accelerate wear and tear on certain components, which are replaceable. (Plus, damage obviously caused by overdosing can void the warranty.) Common examples include:

• Cosmetic decals/appliques discoloring, bubbling or peeling (pictured left).
• Foam headrests/pillows deteriorating or blistering, especially near the water line (pictured middle).
• Rubber seals or gaskets inside of diverter valves wearing out prematurely.
• Valve covers appearing dull or faded (pictured right).
• Jet faces below the water line appearing dull or faded compared to jet faces above the water line.
• Hot tub cover becoming discolored or “bleached” underneath in a short period of time.
• Stainless steel parts rusting or pitting.

Beyond the hot tub itself, you might experience mild physical discomfort, such as eye or skin irritation, dry or brittle hair, or a strong chemical smell. Bathing suits may also wear out or fade prematurely. Would this mean you should stop using sanitizer altogether? Actually, sanitizer is required to maintain clean, safe water. But you are not without options.

Several different sanitizers are approved for hot tub use. But you may prefer one over another, perhaps due to sensitive skin. Target levels are measured in parts-per-million (ppm) using the appropriate test strip:

• Chlorine (dichlor) has been in use the longest, but is less preferable for people with sensitive skin. Using six-in-one test strips, the target level for “free chlorine” is between 3-5 ppm. Free chlorine above 5 ppm is too high.
• Bromine is more stable in hot water than chlorine. It is available in granules, or automatic slow-dosing cartridges which are preferable for people with sensitive skin. (See ConstantClean+.) Using six-in-one test strips, the target level for bromine granules is between 4-6 ppm. Using Frog® Serene® test strips for bromine dual-cartridge (in-line or floating) systems, the target level is between 1-2 ppm. Bromine above 6 ppm is too high.
• SmartChlor® (pictured above) is the latest sanitizer developed. Due to its unique molecular structure, it remains effective at lower concentrations than bromine or chlorine. In the United States, it is available in automatic slow-dosing cartridges which are preferable for people with sensitive skin. (See ConstantClean+.) Using Frog @ease® test strips, the target level for Smartchlor dual-cartridge (in-line or floating) systems is between 0.5 to 1 ppm. This translates to a light green color reading on the test strip.

What about salt? Saltwater systems generate sanitizer by converting sodium chloride into chlorine, or sodium bromide into bromine. Several major manufacturers promote the misconception these systems are “chemical-free” or “maintenance-free.” Go here to get the facts.

If your sanitizer level is too high, follow these steps to reduce it:

• Ventilate: Remove the spa cover and run the hot tub jets on high for 30 minutes. Then, test the sanitizer level again to confirm the reading is back to normal.
• Dilute: If the sanitizer level is still too high, turn off the jets and drain your hot tub about halfway.* Then, add fresh water to dilute the remaining sanitizer. After refilling with fresh water, run the jets on high for 30 minutes and then test the water balance and sanitizer level again as noted on the test strip. (To avoid stressing sensitive plants, shrubs or lawn, route your drainage hose accordingly.)

What if your sanitizer level is within the recommended range, but it seems like your hot tub is using too much sanitizer? Here are some common reasons:

• Your hot tub gets used several times per week.
• Your hot tub is frequently used by multiple people.
• Your guests do not typically rinse off before soaking.
• Your hot tub cover gets removed for long periods of time (such as during parties or barbecues).**

Naturally, the more often a hot tub is used the more sanitizer it will consume. This is not a bad thing; it just means your sanitizer is doing its job. That said, two simple habits will help to reduce sanitizer consumption:

• Rinse off in the shower before soaking. The less body oil, lotion, hair products and deodorant you bring into the water, the less sanitizer your hot tub will consume.
• Keep the cover on whenever the hot tub is not in use.

Is there anything else you can do? If your hot tub is not equipped with an in-line sanitation system, you might consider using a dual-cartridge floating system (mentioned earlier) which may help to decrease sanitizer consumption.