If required they can be cleaned out twice a day when high temperature and high feeding rates are present and can also be cleaned out monthly when low temperatures and low feeding rates are applied.
They cannot possibly ‘block’, the running costs are extremely low and nor do they have any moving parts to consider.
I have often been accused of openly ‘slating’ other filter designs.
When I believe that explaining in great detail, to others, as to why they do have various shortcomings is perfectly good and valid information.
Or should I pretend I don’t know, and say nothing?
For instance, our rivers do not flow uphill – but they do give perfect and constant coverage of ALL the ‘static’ surfaces as they pass by horizontally.
If we really do wish the water in our filters to perform ‘party tricks’ then the very best way we can do this is to ‘pump it’ through an upward-flow box or upward-flow boxes.
The downside of this is, by making water do what it doesn’t want to do, will result in only a very small percentage of the static media surfaces within the box coming into constant contact with the water flow passing through.
Remove the static media surfaces and replace with moving media surfaces and this significantly reduces the chance of constant water contact with ANY of these surfaces.
Rivers can easily be controlled to pass through static areas of biological surfaces if ever that is required and, in my biological filters, it is required.
Rivers, from time to time, also fall downwards by way of waterfalls and man-made weirs/dams but falling water is not nearly so easy to control/harness with any real accuracy. Most of the real natural benefits of these in a river system are to greatly increase dissolved oxygen content.
There are Koi keeping terms and statements that have been bandied around for many years now, such as –
‘New Pond Syndrome’ (NPS).
‘The moment a Koi leaves the breeder, it starts to deteriorate’.
I don’t know who invented the first three terms but the last two were definitely invented by a person who wished to peddle a pond water conditioner.
The word ‘Stress’ is even a bigger cop-out than the word ‘Genetics’, ‘Stress’ can come to the rescue of just about anything we care to mention with our Koi.
One thing I’m sure of, I’ve yet to see a single Koi die because of ‘Stress’.
I’ve seen Koi jump out of a pond and die – that’s not ‘Stress’.
I’ve seen Koi die through an overdose of anti-parasite medications – that’s not ‘Stress’.
I’ve seen Koi die through toxic water conditions – that’s not ‘Stress’.
I’ve seen Koi die by flock spawning or parasites – that’s not ‘Stress’.
I’ve seen Koi die because of a lack of dissolved oxygen content – that’s not ‘Stress’.
Do you wish me to continue?
Koi don’t have to work in order to pay mortgages.
Koi don’t have to support and feed their families, nor do they need to buy clothes.
There’s no such thing as ‘Stress’ where Koi are concerned because there’s always a specific reason for Koi deaths or damages.