If the disinfection system is working and the filters are functioning, a whirlpool must have clear water! 

"Whirlpool water must never be cloudy!"

Therefore, I will explain each point here individually in order, which can be checked and improved to ensure that everything works.

AGAINST CLOUDY WHIRLPOOL WATER

pH value setting correctly to combat cloudy turbidity of the whirlpool water

The pH value in a hot tub should always be between 6.8-7.2, as otherwise, any disinfectant is severely limited in its function. Hot tub water becomes cloudy at pH values that deviate 0.5 from 7.0. The hot tub water becomes milky cloudy. From a deviation of 1.0, it becomes completely milky. Attention: Many pH meters measure incorrectly if the TA value is not correct. This is the most common mistake in hot tub water care.

Disinfection against greenish, brownish cloudy hot tub water

Color with insufficient disinfection - green, brown cloudy

Chlor, Brom, Active Oxygen
It is important that ozone and chlorine/bromine should not be mixed together permanently! Both chlorine/bromine and ozone form free atoms that seek a bond (preferably with carbon = bacteria, algae, etc.), and when both are used simultaneously, it can happen that chlorine binds with oxygen instead of the atoms attacking the "bad, living" substances in the carbon water.

• UVC - UV System: make sure that the glass tube through which the water is irradiated is not fogged or dirty. This would reduce the radiation and significantly diminish the disinfection effect.
• Ozon System: The probably simplest, most efficient, and healthiest way to disinfect hot tub water, when a few simple things are taken into account.
• Disinfection times: Always set to 24h circulation and ozone runtime at the beginning. If the water is perfect or in case of infrequent hot tub use, the times can also be reduced.
• Ozonator: Different ozonators have different ozone production amounts. Choose the right ozonator.
• Check if the installation direction of the ozonator fits (this is important for whirlpools with ozonators with membrane pumps!) and whether it is also functioning (usually indicated by a green control light).
• Check if the intake side of the ozonator fits. Often, the intake holes are designed to be much too small or covered with fibers for reducing air humidity, which quickly stick together. Drill the intake hole to at least 3mm and remove the fabric piece on the intake side.
• Ozone mixing: This is done using Mazzei injectors, which operate with the Venturi vacuum system and are connected to the ozonator via a hose line with a check valve.
• Mazzei Injector: The choice of the right injector and the correct water flow rate at the injector are important here. This can be influenced as follows:
• Alternative backflow options should be prevented so that as much water as possible must pass from the circulation pump past the injector. Often, waterfalls or hot water return lines are also connected to this circuit. Turn off the waterfall when not in use! If possible, turn off the hot water return nozzle as much as possible (this is often done using a hemisphere located at the tip that is positioned against the flow)!
• Ensure flow in the ozone line: some hot tubs have mixing chambers that can become dirty or clogged with biofilm over time. Remove these mixing chambers. Ozone acts for 20 seconds. This means that whether with or without a mixing chamber, the return should last at least 20 seconds. This can be easily tested by covering the ozone intake and measuring how long it takes for ozone bubbles to reappear in the pool after releasing the intake.
• Check that the non-return valve in the Mazzei injector is not clogged or stuck with dirt and therefore does not open sufficiently.
• "Connection line Ozonator - Injector: These two components are connected with a hose line with a check valve."
• Check whether the hose line is fully permeable (not kinked, not laid with dirt or nitric acid compounds (which form as a sticky film in the hose during ozone generation))
• Check if the check valve in the line is fully permeable. Remove, wash out, and blow through.
• To avoid an erroneous intake of air instead of ozone at the piping connections, all connection points can also be sealed with insulating tape.

And the most important point against cloudy hot tub water:

the right hot tub filter against cloudy whirlpool water due to unfiltered suspended particles

EGO3 Filter (+++): Can hardly clog, as they do not function like a filter mesh of paper filters (cartridge filters), but rather according to the principle of turbulence along free flow channels. They filter out everything down to 1 micrometer in enormous quantities, as the entire 3-dimensional space of the filter balls is available as a filter area. Furthermore, these filter balls are much easier to clean and you can see if they are clean.

Paper filter (-): When the filters become clogged, the flow rate is naturally reduced, and the suction at the injector decreases, which also reduces the ozone supply. Filters are difficult to clean, as sticky substances cannot be removed mechanically, but only chemically. It is better to replace filters more often than too rarely. The filter effect is limited by the fiber mesh size. The absorption capacity is limited by the relatively small filter surface area. It is almost impossible to visually determine whether the filter has really become clean. Just because the filter is lighter again does not mean that the pores of the filter fabric are also free again.