-------how can I do ozon in the water.Its enough to buy a air pump for aquarius for fish. ore i have to buy a special air pump to ozon the water?--------
An air pump will not give you ozone in water by itself. You need and ozonator to change the oxygen in air to ozone by an electrical or ultraviolet charge. This ozone, which is still a gas is then sent from the ozonator by tubing to a diffuser which is placed in water. The ozone gas coming through the diffuser creates small bubbles of ozone in the water which contact the molecules of water. Some of the molecules of water will take on an extra atom of oxygen in the process.
You may want to take a look at an article I wrote which explains the differences in ozonators and their applications at http://www.ozonatedoilonline.com/generator.html
Golfegg made a good recommendation for an ozonator in his post, but there are a lot of units to choose from if you want to look around cyberspace.
I hope this helps and best of good luck.