Water Balance
What is balanced water?
Water can be corrosive, and eat away at pool & hot tub surfaces and equipment, or be scaling, and deposit crusty or coarse substances on pool & hot tub surfaces and equipment. Water that is either corrosive or scaling is called unbalanced water, while water that causes no damage is called balanced water.
Unbalanced water can also cause skin and eye irritation for users.
Testing your water:
When testing your water always perform all tests prior to adding any chemicals to the pool or hot tub.
We recommend using a Taylor K-2005 test kit. Using this test kit you can perform all of the most common tests for your pool or hot tub. The book that is included with the test kit will help you to deal with common water balance issues. It will also help you calculate the correct amount of each chemical to add to your water based on to size of the pool or hot tub and the readings you collect when testing your water.
Are your readings correct?
1. Sanitizer: Bromine or Chlorine: Suggested range 1.0ppm to 3.0ppm.
False readings: Extremely high levels of chlorine or bromine will cause the indicator solution to bleach out and become clear, causing the test to read 0ppm of sanitizer when it is actually higher than the top reading on the scale.
2. pH: Suggested Range is 7.2 to 7.6 with 7.4 being ideal
False readings: High levels of chlorine or bromine can cause the pH indicator to turn dark purple when the water is actually acidic. Unfortunately, some people think the water is too alkaline and mistakenly add acid to the water.
3. Total Alkalinity: Suggested range is 80ppm to 120ppm.
False readings: High levels of chlorine or bromine can cause the Alkalinity indicator to turn light green or yellow instead of dark green or red.
4. Calcium Hardness: Suggested range is 200ppm to 300ppm for a pool and 150ppm to 200ppm for a hot tub.
How do you know if your water is balanced?
In most cases if your readings are within the suggested ranges your water is probably balanced. How do you know for sure?
With the readings you collected form your water tests you can use the Langelier Saturation Index formula (below) to calculate if your water is balanced or unbalanced.
| SI = | pH + | Tf + | Cf + | Af - | TDSF |
|---|---|---|---|---|---|
| Saturation Index | pH as Tested | Temperature Factor | Calcium Factor | Alkalinity Factor | TDS Factor |
Using the chart below, and your readings, fill in the formula to calculate the Saturation Index (SI) of your water.
*NOTE: Total Dissolved Solids (TDS): How do you find your TDS? You can purchase a TDS meter to check your TDS or you can guess based on how old your water is. In most cases the older the water is, the higher the TDS will be. When the TDS gets too high (above 1500) you usually have a hard time getting the water to stay balanced, and end up using more chemicals than normal to get your water balanced. Sometimes its easier, and less expensive, to change out the water and start over.
| Temperature | Calcium Hardness | Total Alkalinity | |||
|---|---|---|---|---|---|
| °F | Tf | ppm | Cf | ppm | Af |
| 32 | 0.0 | 25 | 1.0 | 25 | 1.4 |
| 37 | 0.1 | 50 | 1.3 | 50 | 1.7 |
| 46 | 0.2 | 75 | 1.5 | 75 | 1.9 |
| 53 | 0.3 | 100 | 1.6 | 100 | 2.0 |
| 60 | 0.4 | 125 | 1.7 | 125 | 2.1 |
| 66 | 0.5 | 150 | 1.8 | 150 | 2.2 |
| 76 | 0.6 | 200 | 1.9 | 200 | 2.3 |
| 84 | 0.7 | 250 | 2.0 | 250 | 2.4 |
| 94 | 0.8 | 300 | 2.1 | 300 | 2.5 |
| 105 | 0.9 | 400 | 2.2 | 400 | 2.6 |
| 800 | 2.5 | 800 | 2.9 | ||
| TDS Factor | |||||
| TDS < 1000 ppm = 12.1 | |||||
| TDS > 1000 ppm = 12.2 | |||||
The ideal result would be SI = 0 (perfectly balanced water).
Balanced water is between –0.3 and +0.3.
Corrosive Water is –0.4 and lower.
Scaling water is +0.4 and higher.
If your water is corrosive or scaling you need to adjust one or more of the chemicals in your water so that it becomes balanced.
Cloudy Water:
Cloudy water can be a result of unbalanced water or incorrectly operating pool equipment. The most common cause of cloudy water is a large influx of organics or dirt into the water and insufficient sanitizer levels to deal with that influx.
Shocking a pool or hot tub is performed to clear the water of organics and dirt by oxidizing them. When shocking your water, always make sure that your water is balanced first, and then if needed shock with granular chlorine based on the chart included in the book that came with your test kit.
Dirty or damaged filters, clogged skimmer and pump baskets, and damaged circulation pumps can also cause your water to become cloudy. Remember to clean your filter, and empty your baskets at regular intervals and repair or replace damaged filters and pumps to prevent cloudy water and possible damage to other pool or hot tub equipment or your pool & hot tub surfaces.