Hot Tub Frequently Asked Questions

We’ve compiled a list of hot tub frequently asked questions. Still have a question? Feel free to stop by one of our locations in St. Charles, Crystal Lake or Palatine or click below.

How often should I clean my filters?

Best Practices

Typical rule of thumb is every 4-6 weeks, regardless of usage. Even when not in use, the water is continually moving and circulating and you’re still filtering impurities that occur naturally in the water.


Use a filter cleaner/degreaser, not just water. Even though literature states that Tri-X filters are dishwasher safe, they still require degreasing on a regular basis.

How long do filters last?

Typically 2-3 years if properly maintained, cleaned and rotated in different stations on a regular basis. If filters are neglected, this often leads to clogging which may cause overheating or flow restriction. In any case, it’s can cause serious damage and repair issues.

What does a flashing power light (red/blue) indicate?

Dirty Filter

The most common cause of this would be a dirty filter.

How to Check It

The best way to check for this is to turn off the breaker, take the filters out completely, turn the breaker on and check to see if the light is solid.  If it stays solid, simply clean/replace the filters and be sure to clean them again in another 4-6 weeks.

Call Us

If within minutes it starts to flash again, contact our Service department for a more thorough diagnosis.

What does a flashing power and ready light (red/blue and green) indicate?

Simply, no flow. Once again, 99% of the time it means your filters are needed. Follow the same procedure as in Question #3. In rare occasions, when draining, cleaning and refilling the spa, you may see this light come on which indicates an air lock.

How often should a spa be drained and refilled?

Typically every 3-4 months. If you think about it as something to be done at least once each season, you’ll be on schedule.

The formula is:

  • Number of gallons of hot tub
    Average daily bather load and/3 = How many days between drain and refills
  • 500 gal. Grandee used every day by 2 people/3 = 83 days which is about 3 months

How long does a silver ion cartridge last?

They last 3 months, but if they dry out, they are no longer effective. In other words, always make sure that they remain submerged in water if you must remove the filter for any reason. A good rule of thumb is to replace the silver ion cartridge whenever you drain and refill your spa.

During the hot summer months, what can I do to cool the water?

  1. Watkins has a built in feature called summer-timer mode. Consult your owner’s manual for this feature. Just remember to revert back to normal operation in the fall. Of course, water never cools lower than what the ambient temperature is.
  2. Turn the breaker for the heater off.
  3. Open the cover at night and let it breathe.

We’ve had some really cold winters, is there a limit on heating the hot tub?

No, a spa heats to 104° regardless of the outside temperatures. Normally the spa heats 2-4 degrees an hour with the cover on. While you’re in the tub, the water temperature may drop slightly, but shouldn’t be noticeable for an average spa soak of 30 minutes or so.

I keep adding chlorine, but can’t hold a residual. Why?

Chlorine is not stable in hot water and quickly dissipates after killing the bacteria.  Be sure to follow the recommended doses for your size hot tub on a consistent basis.

frequently asked questions