Its a special device called an oxoneater. I am not an expert on it but as i understand it the device takes O2 (Oxygen) and turns it into O3 (Ozone). Ozone is very unstable and is harmfull to living organisims.
Basicly what happens is the water from the filter go through the ozone device that releases just enough ozone to kill bacteria and what ever else in the water....So the water is purified or sterilised is propably a better word....To stop the O3 from getting into the pond and killing the koi a foam fractionator (protein skimmer) is used to release the O3 and change it back into O2 before the water returns to the pond. The protein skimmer used must also be made of a special type of plastic or the O3 will breakdown (carrode) the plastic.
There are several diffirent types of oxoneaters. There has been several accidents with Ozone overdosing in the past and so in general its viewed as a dangerous device but there are diffirent versions that work diffirently that are suppose to be safer.
Home 
Calendar
