How-To Guides | Cleaning, Balancing & Maintaining your Hot Tub Water

Preparing your spa involves three basic steps: cleaning your equipment, balancing your water, and initiating your sanitizer system. We'll guide you through the easy procedures.

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Draining & cleaning your hot tub
Balance pH, TA, metals & hardness
Sanitizing your hot tub


Draining & Cleaning your Hot Tub

Always prepare your spa for adjusting the water chemistry with a thorough cleaning. Regular upkeep not only makes spas easier to treat with chemicals but also extends the life of internal parts. Repeat this process with each spa water change, or every 60-90 days.

Supplies needed:


  • Remove filter(s). Replace if older than 1 year, otherwise soak in Power Soak or ecoTUB Filter Soak, then set aside to dry.
  • Add 8oz. Spa System Flush to the water and turn the jet pump on for about 15 minutes, or let sit overnight.
  • Drain your tub.
  • Reinstall filter cartridge. Keeping an extra or two on hand means you'll always have a clean, dry filter to install.
  • Clean inside the tub & both sides of the cover with a mild, pH neutral cleaner, like ecoTUB Spa Clean spray. Note: Avoid common household cleaners. They cause foaming & alter the pH balance of hot tubs.
  • Treat spa shell with Gel Gloss or other non-wax polish.
  • Apply 303 Protectant to both sides of spa cover. Never use vinyl conditioners containing petroleum distillates or silicone.

Time to replace your hot tub cover?

Tattered, smelly or heavy covers not only have poor insulating value, they also harbor fungus and microbes, polluting spa water. Replace your cover before it becomes an emergency.

DuraTherm Custom Hot Tub Covers


Balance pH, TA, Metals & Hardness

Cleaning your spa and replacing the water doesn't mean it's good to go. Even good sources of tap water still need to be adjusted to meet the requirements of hot tubs.

You may not need all of the supplies listed below, depending on your sanitizer system and water source.

Supplies for testing & prepping spa water

Supplies for balancing the water:

  • Alkalinity Increaser - raises low TA & pH; helps control pH
  • pH Decrease - lowers pH
  • pH Increase - strongly raises pH (optional - use Alkalinity Increaser for more minor adjustments)
  • Increase Calcium - raises calcium hardness*

*not required for the Cleanwater Blue system


  • Refill about half full with fresh water. Use a hose filter for well water.
  • Add Metal Stain Preventer, clarifier & scum digester per label instructions & finish filling spa.
  • Use test strips & adjust using chart below.
  • After balancing, let water circulate for at least 30 minutes before retesting & making final adjustments.
  • Test for calcium hardness. Add Increase Calcium to about 150 PPM if too low.
  • Add shock to the spa per label directions.
  • Place a floating oil scum absorber in spa water.

Balancing pH & total alkalinity

Always balance total alkalinity (TA) first.

TA Range:

  • 30-90 PPM for Cleanwater Blue system
  • 80-120 PPM for Bromine or Nature 2 systems

If TA is low, add Alkalinity Increaser until the TA nears the upper end of the appropriate range.

If TA is high, add pH Decrease until the pH nears the upper end of the appropriate range.

Notes: TA on the high side is less of a problem than TA on the low side. Allow time for chemicals to distribute through the water. In the case of extreme high pH/TA that doesn't change with pH Decrease, try Acid Magic.

Adjusting pH:

The ideal range is 7.2 - 7.6.

Check for pH level after TA is balanced. Adjusting TA often brings pH into line.

  • Below 7.2: add more Alkalinity Increaser until a reading of about 7.4 is reached. pH Increase is great to use if both pH and TA are very low. It's important to note that both pH Increase and Alkalinity Increaser will also raise TA. If TA is already high, you can try Magnesium Oxide, which will significantly raise only the pH.
  • Above 7.8: add pH Decrease until a reading of about 7.6 is reached.

Remember: pH that's a little high is much less of a problem than pH which is too low (acidic). Low pH causes harmful corrosion; high pH contributes to scale formation, but that's much less of a problem. Properly balanced water will also have a better feel on the skin and allow your sanitizer to perform.


  • Set your hot tub filter cycle for at least 3-6 hours per day.
  • Add clarifier and/or scum digester products weekly per label directions.
  • Always add each chemical to the spa water one at a time - NEVER mix them together.
  • Test spa water weekly and readjust if needed.
  • Read and follow all label directions and cautions.

Sanitizing Your Hot Tub

The type of water purification used in your spa is a personal choice. Here we list our three preferred sanitation systems. Whether you use another chemical or one of our favorites, carefully read and follow the instructions on the package.

NOTE: Directions for each of the 3 different systems we recommend are shown below. For help in choosing the right sanitizer for your spa, read our Spa Sanitizer Comparison Guide.

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Bromine System
Cleanwater Blue System
Nature2 System

Bromine System

Conventional Tablet Sanitizer

Bromine tablets are loaded into a handy floating bromine feeder for mixing with the water.

Supplies needed for Bromine system:

Bromine Procedure:

  • Follow Draining & Balancing procedures above.
  • Add granular bromide (1 teaspoon per 200 gallons of water). This establishes an immediate bromine reserve.
  • Load 3-4 bromine tablets in adjustable bromine float. Each dispenser has different adjustment increments, so start small and follow instructions if applicable.
  • Test bromine level after several hours with spa circulating. Increase or decrease level to maintain 3-5 PPM. Do not allow to fall below 3 PPM.
  • Shock weekly with OxySpa non-chlorine shock, per label directions-- generally about 1 1/2 - 2 oz. per 500 gallons. (2 tablespoons = approx. 1 1/2 oz).
  • Test weekly.

Get everything you need in one kit with the Bromine Pro Starter Kit. Includes step-by-step instruction card.

Cleanwater Blue System

Advanced Alternative Odor-Free Liquid Sanitizer

Cleanwater Blue is an easy-to-use, healthy alternative mineral water purifier in liquid form. It works by releasing mineral ions into the hot tub water. One bottle lasts 4 to 6 months. (Note: Replaces old RainForest Blue system).

Supplies needed for Cleanwater Blue system:

Note: Cleanwater System products are supplied with handy dosage cups & easy instructions.

Cleanwater Blue Procedure:

  • Follow Draining & Balancing procedures above.
  • Determine spa water volume while refilling, per easy supplied instructions in your Cleanwater Blue box.
  • Add 1 tablespoon Oxy Spa non-chlorine shock per 150 gallons.
  • Add 1 teaspoon Dichlor per 250 gallons at startup (optional, but recommended).
  • Add 10ml Cleanwater Prep per 100 gallons, clean filter per supplied instructions.
  • Add 5ml Cleanwater Blue per 100 gallons.
  • After the first 2 weeks, add 5ml Cleanwater Purge twice a month.
  • Test every 2 weeks.

Nature2 System

Alternative Odor-Free Cartridge Sanitizer

The Nature2 spa purifier fits inside your spa filter cartridge. It sanitizes by releasing minerals into the water and lasts for 4 months.

Supplies needed for Nature2 system:

Nature2 Procedure:

  • Nature2 sanitizer cartridge
  • Chlorine test strips
  • Follow Draining & Balancing procedures above.
  • Install the Nature2 cartridge in your filter per the instructions in the box. Run the filtration cycle at least 4 hours a day.
  • Shock the spa using dichlor chlorine at a ratio of 1.5 tablespoons dichlor per 250 gallons.
  • Test water with chlorine test strips, waiting until chlorine level has dropped below 5ppm before using the spa.
  • After each use, add 1 tablespoon Oxy Spa per 250 gallons.
  • Test & balance weekly.
  • Replace cartridge every 4 months.

Get everything you need in one kit with the Nature2 Pro Starter Kit. Includes step-by-step instruction card.