Ozone and Koi ponds
Ozone is probably the most abused and poorly understood topic when it comes to Koi ponds. On paper, ozone looks promising and indeed most appealing.
However, the practise is often far from perfect.
Ozone requires careful monitoring in order to be effective. It requires ongoing maintenance and adjustment to suit the ever changing needs of your Koi pond and, most importantly, you need to ensure you have the right levels of ozone in your Koi pond.
Also called activated oxygen ozone is an isotope of oxygen in that a third oxygen atom attaches itself to normal oxygen (O2) as we understand it resulting in a molecule now composed as O3+.
What this means is that you actually have a highly unstable chemical that wil basically react with anything it finds in its path to oxidise itself back to normal oxygen (O2) and a by product of whatever it has just encountered to get rid of the extra oxygen atom.
Ozone is highly reactive and one of the strongest oxidation agents with an oxodising factor of 2.6. Fluorine is the strongest known oxidant with a factor of 4 by way of interest.
The idea behind the use of ozone in Koi ponds is as we say appealing. Ozone will react with ammonia, nitrite, nitrate, viruses, small bacteria, stray heavy metals and pretty much everything else it comes into contact with, either precipitating it out of solution or rendering it into something more useful such as free nitrogen gas or dead viruses.
Pure ozone is not dangerous to living organisms in the kind of quantities found in Koi ponds. But this doesn't mean it is not dangerous - remember that anything in excess is poisonous.
So what are our concerns around Ozone?
Well, to be frank, if ozone was as easy and as simple to use as claimed, and if it were the wunder drug for Koi ponds, we'd expect to have seen a lot more ozonisation systems on a lot more Koi ponds.The fact of the matter is that maybe one Koi pond in a thousand has ozone being used somewhere on the Koi pond system, and it probably doesn't even need it.
Ozone is expensive to generate properly. Cheap Ozone systems are a waste of time and will last a year or so before gracelessly terminating having all the while produced less and less ozone as they slowly expire.
Ozone requires considerable expensive expertise to specify correctly. To get the correct ORP reading (ozone level) in your Koi pond is nigh on impossible because over time the levels of waste contaminant in your pond fluctuates - such that as your Koi population grows your ORP levels need more ozone to maintain themselves. In winter as things slow down you need less ozone in theory.
What this means is that you typically need an excellent ORP monitoring system. These can get seriously expensive, and when combined with the proper equipment required to generate ozone properly, you're in a for a significantly fat bill to do the job your bacteria do for you anyway.
And then there is the means of getting the ozone, as a gas, into your water system without it all simply bubbling up to the surface and blowing away into the wind. Dissolving oxygen or ozone into water takes time and venturi systems and the like that are commonly used are in our humble opinion, inadequate with the result that most of your hard earned ozone is simply transferred to the atmosphere.
Don't get me wrong. Ozone CAN play a role in a Koi pond environment. However, we have yet to see an installation that relies on ozone as a primary element in the filtration or water quality management. We have seen one or two instances where it is used a secondary element, but in all cases simply switching it off makes just about zero difference to the operation or the water quality of the Koi pond.
The result is that we have yet to be convinced about the debate that is ozone in Koi ponds. Having tried it ourselves on numerous occasions, we remain open to suggestions on it.