looking for an ozon generator!!!

Hello I am looking for an ozon generator to buy,if you guys could post the names of the medical grade and not medical ones which you think are the best I will be very greatfull.Links would be very helpfull.There is so many of them on the market that I am really confused which one to buy,so I want to investigate both medica and non medical brands and choose the best one ,I pretty sure that there is many of you who own such a generators and know a lot about their quality.Thank you.
One more question ,can drinking ozonated water help with candida and once the water is ozonated how long it can be stored?Also If I ozonate the water is some kind of meter needed to measure the ozon in the water or even to much ozon in the water is not harmfull?Thanks a lot.