AquaTerra Fairfax, Owner'S Manual

16

ADDING START-UP CHEMICALS

WATER CHEMISTRY GUIDELINES

The following step-by-step instructions are a recommended guideline for balancing water 

chemistry. If unsure about any step in the process, please contact a Customer Care Associate 

at (888) 961-7727 Ext. 8440.  
Initially, it is advisable to identify what minerals (e.g. iron) are present in the local source water. 

This will provide a better understanding of how to treat the water. Please follow the four steps 

below and be sure to achieve the correct levels in each area before moving onto the next step. 

STEP #1: ESTABLISH PROPER PH LEVEL: 

The recommended range for pH is between 7.2 and 7.8. If the reading is too high, lower the 

pH by using a pH Down/Decreaser (sodium bisulfate). If the pH level needs to be increased, 

do so with a pH Up/Increaser (sodium hydrogen carbonate). Any pH Up or Down should be 

added one teaspoon at a time, waiting one-half hour between application and re-measuring. 

STEP #2: MEASURE TOTAL ALKALINITY:

The ideal range is between 40-120 parts per million (PPM). If the total alkalinity is too 

high, it should be reduced by using an Alkalinity Down/Decreaser (sodium bisulfate). If the 

total alkalinity is too low, it can be increased by adding an Alkalinity UP/Increaser (sodium 

bicarbonate or sodium hydrogen carbonate). These products should be added in small 

amounts – a teaspoon at a time. After adding one teaspoon, wait one half hour before 

re-measuring. Once the safe range of total alkalinity is established, proceed to the next step.

STEP #3: DETERMINE CALCIUM HARDNESS:

It is important to bring the calcium reading to between 50-150 PPM. If the reading requires 

adjustment, it should now be corrected.  If the water is too soft (a low reading) calcium 

hardness should be added to the water to increase the PPM reading. If the water is too hard 

(a high reading), it can be corrected by either: (A) a mixture of hard and soft water added 

to attain a reading in the safe range, or (B) addition of stain and scale control. If calcium 

hardness is a problem with the local source water (either too hard or too soft) a test kit, which 

measures calcium hardness, is essential.

STEP #4: SANITIZING: 

After steps 1-3 are complete, 

the spa must be sanitized using Chlorine (sodium dichlor)

. 

Add 2 teaspoons of Chlorine, and increase as necessary to reach a level of 3-5 ppm.  Check 

and maintain this level weekly, and before and after using the spa. 

IMPORTANT NOTE:

A 

granulated sodium dichlor is highly recommended for sanitizing spa water, granular bromine 

may also be used.

Never use compressed sanitizers even with a floater

. 

As with any other 

chemicals, the sanitizer should be introduced to the spa with the jets running for 10 minutes.

WEEKLY SHOCK:

Using a potassium monopersulfate (MPS) shock, add approximately 2 oz. spreading it over 

the water while the jets are running. Shocking is achieved by adding the MPS to turbulent 

water. Leave the cover up and jets on high for 10 minutes. Then shut jets off and return the 

cover to the closed position to maintain heat. Then return the cover to the closed position to 

maintain heat.