Testing indoor hot tubs water is very important since it allows us to balance the chemical properties so that it is neither too alkaline nor too acidic (as we discussed earlier), for both comfort and equipment protection. As we know, if the pools and large hot tubs water is ignored for a significant period of time, then you’re risking unsafe and unsanitary large hot tubs water conditions. Testing also allows us to maintain a spa sanitizer maintenance system to ensure healthy water for large hot tubs that is free of heavy metals and dangerous bacteria.
It is a good idea to adjust alkalinity in your large hot tubs water first, and then we look at pH. (Balancing total alkalinity of indoor hot tubs usually brings pH in line). We have already discussed the proper procedures of balancing large hot tubs water under the pH section, the calcium section, alkalinity section, and the heavy metal section. After adding proper additives and decreasers, it is then time to test the water to make sure everything is at a correct level in your indoor hot tubs.
Some of these testing kits have you take a small sample of your pools water, place a couple drops from the testing kit into the sample of your indoor hot tubs water, and then the sample will turn a certain color which tells the balance of the pools water according to the chart. Another common testing kit for large hot tubs is testing strips. These are simply placed in the pools water and will change color. Once the new color appears on the testing strip, you match it with the similar color on the testing kit chart and make an analysis. The steps you take for the testing strips are as follows:
- Allow your indoor hot tubs water to circulate for a minute or two, then take a sample of the large hot tubs water in a clean plastic cup—fill it about half way, or just enough to fully dip the strip into it.
- Remove an indoor hot tubs test strip from the bottle, and recap tightly (this will be important for the next time you use them in order to keep them fresh and effective).
- Dip the strip in the water just deep enough to wet the test pad used, and remove according to bottle instructions.
- Remove excess water by shaking the strip once
- Hold strip horizontal, pad side up, for 15 seconds (or however the bottle instructs you to).
- Make color comparisons with testing kit chart.
- Adjust your indoor hot tubs water as necessary (using the pH, alkalinity, calcium, or heavy metal additives).
- For the most accurate results, give large hot tubs water a couple of hours or overnight after adding balance chemicals, then retest to see if it is finally balanced.
A couple key things to remember while you are conducting a pools water test is to be sure that your fingers are not manipulating the indoor hot tubs test strip while you are inserting it into the water. This could give inaccurate test results because your fingers may have been exposed to higher levels of balance chemicals. Also, be sure to properly store your testing strips. Again, make sure the bottle cap is screwed on tightly, to ensure no excess air can get to the strips. Furthermore, store them in a safe place. If storing them outside near your large hot tubs, store them out of the way of direct sunlight, as this could cause damage to the color results. And most importantly, check the expiration date on the bottle!
The indoor hot tubs test strips do expire and you want to be sure you aren’t using a defective strip when testing your large hot tubs water. Below is a useful chart that shows where your water balances should be:
Record your test results for your large hot tubs and indoor hot tubs and refer to the following acceptable range.
| Test | Minimum | Ideal | Maximum |
| Chlorine | 1 ppm | 2 ppm | 4 ppm |
| Bromine | 1 ppm | 2-3 ppm | 5 ppm |
*Some calcium hardness (total hardness) charts will reference between 150-500 ppm. While this is widely considered the acceptable range for pools and spas, 150-250 ppm is the minimum preferred range for all residential and commercial hot tubs.
Regardless of which kind of test you use, owners of large hot tubs should maintain excellent hygiene in terms of water hardness and a well balanced pH level if they desire to extend the life span of their indoor hot tubs. Ultimately, you want the best large hot tubs that you can achieve, and these tests will help with that.
