Additionally, ozonizers create ozone by corona action. They use an electrode inside a chamber that is exposed to a very high voltage... 15,000v or more. That causes what is called the
corona effect. This happens best with dry air, hence the need for dryers.
IMO the danger to the hobbyist in using ozone is not as great as is often described. Ozone is highly unstable, so unstable that it cannot be bottled, that's why we have ozone generators instead of just buying tanks of compressed ozone. It breaks down in an impure environment readily. Therefore, it doesn't persist long in the atmosphere. Ozonizers sold for aquariums usually don't produce ozone at a sufficient rate to cause harm to room occupants.
It is nevertheless highly toxic and basic precautions should be taken. An aquarium is a much smaller environment, so ozone if improperly used can crash an aquarium quite easily. It should always be used with an ORP controller to avoid overdosing.
What is a larger problem is that ozone degrades most plastics and rubbers. It is usually introduced into skimmers and if the skimmer and most things associated with it are not rated for ozone contact, the plastics will degrade to the point of breaking apart if they are looked at the wrong way. Only the very top end skimmers usually carry this rating.
Regardless, ozone will not solve your problem. If the cloudy water is being caused by reduced o2 concentration, ozone may address the clarity to some extent, but you need to solve the problem, not hide the symptom. If indeed o2 is the issue, your fish are probably under a terrible amount of stress, and ozone will not make that go away. Increased water volume and increased air-to-water interface are about the only things I can think of, and they've already been mentioned here.
