The Nexus, Kaldnes Biomedia and The Answer Mechanical Pond Filter

I am not a Koi pond builder or construction expert. I do however know what is needed in a Koi pond and would suggest that if you are serious about keeping large Koi your pond has to be at least 10 000l. Smaller than that please consider keeping goldfish if you don't want to regularly bury Koi. Koi grow too big to be kept confined in smaller environments than 10 000l.

As with all things Koi, bigger is better. Size counts for everything, even with the Koi themselves. Bear this in mind when it comes to selecting your filtration equipment. If you do your homework into the hobby and you do things properly the first time, your Koi will live and prosper and they will grow. This increase in growth places an increased demand on your filtration system. It sounds obvious, but a 40cm Koi 665 grams on average is very different from a 90cm Koi that can weigh 8448 grams on average. That's twelve times the weight of Koi and twelve times more filtration load!

It still amazes me that people still buy biofilters that are 'rated to treat XXX l of pond water'! Such a rating is completely and utterly meaningless. My biggest problem with it is that it is deliberately misleading to the detriment of the purchaser. What if there is only one single fish in this pond? What if there are a hundred? What if these fish are all 10 kg or heavier? What if they're Koi and not goldfish?

The only meaningful rating is one which indicates how many kilograms of Koi fish weight the bio filter is capable of handling, and at what speed (rate) the bio filter is able to breakdown wastes. It's no good if the bio filter takes three days to remove the wastes produced by Koi - no Koi would be very happy at only being fed once every three days! Remember too that Koi on a weight for weight basis produce about twice as much filtration load as goldfish do - Koi are not known as the 'pigs of dams and rivers' without good reason!

My advice is that any bio filter offering a rating based on pond volume is seriously flawed. Stay away. The designers of these so called biofilters have made a guess as to how many fish would be living in such and such a pond volume, and worse, they've guessed how big these fish are. Even worse, if they have made all these guesses, do they in fact know how many milligrams of ammonia the filter is capable of removing per hour at a specified flow rate and under what conditions? My guess is that they have no idea. In modern Koi keeping, this is nothing short of genocide. The one thing that I can promise you is that once your fish load exceeds these guesses, the only certainty is that your local Koi graveyard is going to be doing a lot more business!

There is no substitute for homework when it comes to Koi keeping. It's a lot of fun and tremendously rewarding to see the results in action. Don't be put off, the processes are not that complicated to understand. All it takes is time. Don't be afraid to ask questions and get second opinions.

Do your homework and be rewarded. Fail to do it, and be condemned!

Until next time. For more info visit Happy Koi by clicking here or go to http://www.happykoi.co.za