Here you will find the Gruber 4-point system as well as all the important hot tub water care products you need. Based on the experience of 12,000 hot tubs sold, we can offer and show you the simplest working system after 18 years of experience. Actually, you only need 3 different products to keep your Spa water in top condition. Beyond that, there are many others, which are often unnecessary. These often arose because hot tub sellers are not sufficiently familiar with care and therefore want to sell a variety of chemicals. Here we explain how you can easily keep your hot tub water clean and in perfect condition with normal products. We do not sell hot tub chemicals, so we also advise you properly and competently. However, fundamentally, your hot tub seller is responsible for advising you regarding water care. Therefore, we ask you to refrain from excessive questions to us regarding water care, as this has increased excessively in recent months. Of course, we are happy to help, but we cannot accompany you over a longer period with your water care; that is the task of the hot tub seller. He has earned a lot of money from you and therefore owes you this support. Unfortunately, this willingness or ability to support varies greatly. We would like to commend the companies Armstark, Beta Wellness, Artesian Spas, V&B, WSG, Nordpool here. Their service regarding support even after the hot tub purchase is exemplary.

It doesn't take much to get a handle on the water care of your whirlpool. All you need is some information and the right understanding of whirlpool chemistry:

1. Hard/soft water
2. pH value
3. Disinfection
4. Filtration

Hot Tub Water Care - Part 1 - Hard or Soft Water

It is important to regulate the lime value of your hot tub water, as an unbalanced lime content can cause various problems:

1. If the lime value is too high, the lime can precipitate strongly with rising pH value of the water, leading to deposits and impairing the function of the hot tub.
2. A too low lime value can damage seals in the hot tub over time.
   
   The ideal lime value 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 "medium hard." You should measure the lime value of the water when filling the hot tub and correct it if necessary. Use a suitable measuring tool such as strips or a pool laboratory. The measuring tool will also show you the ideal value. Adjust this value according to the instructions on the lime product you use.
   For correcting the lime value, I recommend the product "HTH Spa Antikalk". Follow the instructions on the packaging to adjust the lime content accordingly.

Hot Tub Water Care - Part 2 - pH Value

Setting the correct pH value is another important step in caring for your hot tub. The pH value 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 value should have stabilized, and you can stop adding it. From then on, you only need to check the pH value occasionally and correct it if necessary.
Do not rely solely on your measuring instruments, as incorrect alkalinity can significantly distort the pH value result, except for a pool lab. The ideal total alkalinity (TA) is 100. For every 10 units deviation of TA downward, you must add 0.1 to the measured pH value. For example: pH 6.9, TA 20 means the actual pH value is 7.7. This is a common mistake in hot tub care, where only the pH value is measured without considering the corresponding alkalinity. So always measure both and adjust the pH value result accordingly.

GURU TIP FOR pH VALUE: There is an easier method: A too high pH value always leads to milky water. Observe the water for milky turbidity. As soon as the water becomes slightly milky (first bluish tint from 7.5, minimally milky from about 7.7, very strongly milky above 8.5 pH), 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 value regulation, we recommend products like "HTH plus" or "HTH minus".

Hot Tub Water Care - Part 3 - Disinfection

Disinfecting your hot tub water is crucial because, with insufficient disinfection, many germs, algae, or bacteria can quickly form due to the warm water.
There are clear signs that your hot tub water is not okay:

1. The hot tub surface becomes slippery.
2. Your water becomes cloudy (dirty), starts to smell, and discolors greenish to brownish. Note that this should not be confused with milky turbidity, which can indicate an incorrect pH value.

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 like "HTH Schockchlor rot" or other suitable disinfectants specially developed for hot tubs. Follow the instructions on the packaging and perform regular tests to ensure that disinfection is maintained.

Step 1 - Control and Removal of Biofilm in the Hot Tub

First important step (usually not necessary for new installations):
BIOFILM: Biofilm forms in all water-carrying pipes. Biofilm is a slimy layer of microorganisms. You might know it from cleaning a drain, where there is a slimy layer inside the pipe. That is biofilm. Why is biofilm a big problem in hot tubs? It continuously releases bacteria and breaks down disinfectants like chlorine. Due to the continuous release of bacteria, water problems are inevitable, no matter how you disinfect.

Therefore, it is crucial that your hot tub is free of biofilm or that biofilm is removed!

To find out if biofilm is present in the pipes of your hot tub, there are two simple methods:
1.) Monitor the chlorine levels in the water: If the chlorine is depleted faster than usual (normally it should be detectable in the water for 4-5 days), this could indicate biofilm in the pipes. Watch for the appearance of white or black soft slimy flakes in the hot tub water. This may indicate that parts of the biofilm have already detached from the pipes.
To remove the biofilm, you need special chlorine, such as calcium hypochlorite, which kills the biofilm. Add the chlorine according to the instructions into the hot tub water and monitor the chlorine content daily. If the chlorine disappears before 4-5 days, repeat the process until the chlorine remains stable for this period. This will eliminate the biofilm.
2.) Biofilm can also be removed by rapid changes in flow in the pipes, such as turning the pump on and off or changing the distributor valve position, as well as by natural detachment from the pipes. In this case, you may notice white or black flakes in the water, which you can remove by filtration through 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 to avoid discoloration of the cover and other plastic parts.

Step 2 - The next important step is the continuous disinfection of your hot tub water:

After your hot tub is now free of biofilm, it is important to distinguish the different types of continuous disinfection:

1.) If your hot tub has an ozone and/or UVC system that disinfects sufficiently and functions properly:
WARNING: The presence of ozone or UVC does not automatically mean that these are properly installed, correctly sized, or operated correctly. Most hot tubs are equipped with ozone, but only about 3-4 manufacturers can guarantee fully automatic disinfection with it. It requires specific expertise and the right configuration to use these technologies effectively. Economic considerations may also play a role. Ozone and UVC have no long-term effect and must therefore be operated continuously, which can lead to high operating costs with powerful circulation pumps.

HOT TUB GURU TIP FOR OZONE/UVC: Purchasing ozone and UVC devices is not worthwhile if your circulation pump consumes a lot of electricity. For a circulation pump with more than 250 watts, the manufacturer can do without ozone and UVC.
- How to know if your ozone device (UVC lamp) is sufficient: If you add no disinfectants to the water and it remains flawless during a 24-hour circulation. If these devices are incorrectly installed or defective, the water will turn bad after 3-4 days.
- What to do if the ozone device works and the water remains stable? Actually nothing. You have a premium hot tub with the best disinfection technology. However, you must take measures against biofilm formation (see above).

2.)If your hot tub does not have an automatic system to maintain water quality: You must perform continuous disinfection manually, using chlorine, bromine, or oxygen. We recommend adding oxygen, as it is odorless and the best solution both health-wise and ecologically. Additionally, you must take precautions against biofilm.

HOT TUB GURU TIP FOR CONTINUOUS DISINFECTION WITHOUT OZONE OR UV SYSTEM: Rely on oxygen. Why do many providers recommend chlorine or bromine? Because they do not consider the connection with biofilm. Oxygen is absolutely sufficient if you take appropriate measures against biofilm. It can become problematic if you have an ozone system but it does not meet the requirements to disinfect alone. Chlorine/bromine and ozone neutralize each other.

Hot Tub Water Care - Part 4 - Filtration

And last but not least, filtration of a hot tub or Swim Spa 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 size of particles that can be filtered) and qualitatively (the amount that can be filtered in a certain period).
- Additionally, filtration should occur as long as possible without cleaning the hot tub filters to ensure that the filter cycle is not overlooked.

It is strongly recommended to use only Ego3 filters, as they are superior to old cartridge filters in all aspects. Ego3 filters can absorb about 4-5 times as much dirt quantitatively as conventional cartridge filters. This significantly extends the cleaning cycle to 4-10 weeks compared to the usual 1-2 weeks with cartridge filters. This means that the cleaning time is only reached when the filter is 90-100% dirty, and not after 1-3 days as with conventional cartridge filters. Neglecting cleaning can, in the worst case, impair the entire hot tub system. Moreover, Ego3 filters filter qualitatively much more effectively. They can filter particles of any size, even those from 0-40 microns, which cartridge filters cannot do. This leads to bathing in technically pure water instead of a micro-dirt soup, and the use of chemicals is reduced.

To avoid impairing the hot tub experience with old cartridge filters, it is strongly recommended to switch to Ego3 hot tub filters.