Hot tub water care - Part 1 - hard or soft water
It is important to regulate the limescale level of your hot tub water, as an unbalanced limescale content can cause various problems:
- If the limescale level is too high, limescale can precipitate heavily when the water’s pH level rises, causing deposits and potentially impairing the function of the hot tub.
- A limescale level that is too low can damage seals in the hot tub over time.
The ideal limescale level for your hot tub water is between 8 and 12 German degrees of hardness.
"soft" = up to 8.4 °dH
"medium" = 8.4 to 14 °dH
"hard" = more than 14 °dH
This corresponds to water classified as "moderately hard." You should measure the water’s limescale level when filling the hot tub and correct it if necessary. Use a suitable testing method, such as test strips or a pool laboratory. The testing method will also indicate the ideal value. Correct this value according to the instructions for the limescale treatment product you are using.
To correct the limescale level, I recommend the product "EGO3 Anti-Limescale". Follow the instructions on the packaging to adjust the limescale content accordingly.
Hot tub water care - Part 2 - pH level
Setting the correct pH level is another important step in caring for your hot tub. The pH level should always be between 7.0 and 7.4.
When filling the hot tub, add a small amount of pH Minus in the morning and evening. After about 3–4 days, the pH level should have stabilized, and you can stop adding it. From this point onward, you only need to check the pH level occasionally and correct it when necessary.
Do not rely exclusively on your testing instruments, as incorrect alkalinity can significantly distort the pH reading, except when using a pool laboratory. The ideal total alkalinity (TA) is 100. For every 10-point deviation of the TA below this value, you must add 0.1 to the measured pH level. For example: pH 6.9, TA 20 means that the actual pH level is 7.7. This is a common error in hot tub care: measuring only the pH level without taking the corresponding alkalinity into account. Therefore, always measure both and correct the pH reading accordingly.
GURU TIP FOR pH: There is an easier method: a pH level that is too high will always cause cloudy, milky water. Watch the water for a milky haze. As soon as the water becomes slightly milky (the first blue tint from 7.5, minimally milky from around 7.7, very heavily milky above pH 8.5), simply add pH Minus once or twice, and the water should be clear again within 1–2 days. However, this method is only recommended for advanced users who already have experience with their pool.
For pH regulation, we recommend products such as "EGO3 plus" or "EGO3 minus".
Hot tub water care - Part 3 - disinfection
Disinfecting your hot tub water is essential, as warm water can quickly promote the growth of many germs, algae, and bacteria if disinfection is insufficient.
There are clear signs that your hot tub water is not in proper condition:
- The hot tub surface becomes slippery.
- Your water becomes cloudy (dirty), starts to smell, and turns greenish to brownish. Note that this must not be confused with milky cloudiness, which may indicate an incorrect pH level.
If you notice any of these signs, you must act immediately to improve the disinfection of your hot tub water. Proper disinfection ensures not only hygiene but also a pleasant bathing experience.
For effective disinfection, we recommend products such as "EGO3 CHC70 inorganic chlorine" or other suitable disinfectants specifically developed for hot tubs. Follow the instructions on the packaging and perform regular tests to ensure that disinfection is maintained.
Step 1 - Checking for and removing biofilm in the hot tub
First important step (normally not necessary for a new installation):
BIOFILM: Biofilm forms in all water-carrying lines. Biofilm is a slimy layer of microorganisms. You may know this from cleaning a drain, where there is a slimy layer inside the pipe. That is biofilm. Why is biofilm a major problem in hot tubs? It constantly releases bacteria and breaks down disinfectants such as chlorine. Because bacteria are continuously released, water problems are inevitable, regardless of how you disinfect.
That is why it is crucial that your hot tub is free of biofilm or that the biofilm is removed!
There are two simple methods to find out whether biofilm is present in your hot tub’s lines:
1.) Monitor the chlorine levels in the water: If the chlorine breaks down faster than usual (normally, it should remain detectable in the water for 4–5 days), this could indicate that biofilm is present in the lines. Look for white or black soft, slimy flakes in the hot tub water. This may indicate that parts of the biofilm have already detached from the lines.
To remove the biofilm, you need a special chlorine product, such as calcium hypochlorite, which kills the biofilm. Add the chlorine to the hot tub water according to the instructions and monitor the chlorine level daily. If the chlorine disappears before 4–5 days have passed, repeat the process until the chlorine remains stable for this period. This eliminates the biofilm.
2.) Biofilm can also be removed by rapid changes in the flow through the lines, such as switching the pump on and off or changing the distributor valve position, as well as through natural detachment from the lines. In this case, you may notice white or black flakes in the water, which you can remove through filtration using the hot tub filter.
3.) Make sure to open the hot tub cover regularly when using calcium hypochlorite to allow excess chlorine gas to escape and prevent discoloration of the cover and other plastic parts.
Step 2 - The next important step is the continuous disinfection of your hot tub water:
Once your hot tub is free of biofilm, it is important to distinguish between the different types of continuous disinfection:
1.) If your hot tub has an ozone and/or UVC system that provides sufficient disinfection and functions properly:
WARNING: The presence of ozone or UVC does not automatically mean that the system has been installed correctly, is correctly sized, or is operated properly. Most hot tubs are equipped with ozone, but only around 3–4 manufacturers can use it to ensure fully automatic disinfection. Specific expertise and the correct configuration are required to use these technologies effectively. Economic considerations may also play a role. Ozone and UVC have no long-term effect and must therefore operate continuously, which can result in high operating costs with powerful circulation pumps.
HOT TUB GURU TIP FOR OZONE/UVC: Purchasing ozone and UVC equipment is not worthwhile if your circulation pump consumes a lot of electricity. With a circulation pump rated above 250 watts, the manufacturer can omit ozone and UVC.
- This is how you know whether your ozone unit (UVC lamp) is sufficient: Do not add any disinfectant to the water and check whether it remains perfectly clear with 24-hour circulation. If these devices are incorrectly installed or defective, the water will turn within 3–4 days.
- What should you do if the ozone unit works and the water remains stable? Actually, nothing. You have a premium hot tub with the best disinfection technology. However, you must take measures to prevent biofilm formation (see above).
2.)If your hot tub does not have an automatic system for maintaining water quality: You must carry out continuous disinfection manually, using chlorine, bromine, or oxygen. We recommend adding oxygen because it is odorless and is the best solution from both a health and environmental perspective. In addition, you must take precautions against biofilm.
HOT TUB GURU TIP FOR CONTINUOUS DISINFECTION WITHOUT AN OZONE OR UV SYSTEM: Choose oxygen. Why do many suppliers recommend chlorine or bromine? Because they do not take the connection with biofilm into account. Oxygen is entirely sufficient if you take appropriate measures against biofilm. Problems can arise if you have an ozone system but it does not meet the requirements for disinfecting on its own. Chlorine/bromine and ozone neutralize each other.
Hot tub water care - Part 4 - filtration
Last but not least, filtering a hot tub or Swim Spas is extremely important for hot tub water care for the following reasons:
It is crucial to remove as much dirt as possible, both quantitatively (the amount that can be filtered within a specific period) and qualitatively (the size of the particles that can be filtered).
It is strongly recommended to use only Ego3 filters, as they are superior to old cartridge filters in every respect. Ego3 filters can hold approximately 20 times as much dirt quantitatively as conventional cartridge filters. This significantly extends the cleaning cycle to 8–10 weeks, compared with the usual 1–2 weeks for cartridge filters. This means that cleaning is not required until the filter is 90–100% dirty, rather than after just 1–3 days as with conventional cartridge filters. In the worst case, failing to clean the filter can affect the entire hot tub system. In addition, Ego3 filters are significantly more effective qualitatively. They can filter particles of any size, even those measuring 0–40 microns, which cartridge filters cannot do. This means bathing in technically clean water instead of a soup of microscopic dirt, while reducing the use of chemicals.
And most importantly: Ego3 filter material is self-disinfecting, so the filter itself does not become a source of germs and water care is made easier.
Hot tub water care - summary
You now know everything you need to care for your hot tub as simply and cost-effectively as possible.
