Filtration in Koi Ponds

In the early 1980’s I was the first to produce ready-made multi-chamber upward-flow units simply as a ready-made copy of systems I’d seen in Japan – the Cockney Koi units sold today are exact copies of my early 80’s multi-chamber units. I continued to produce upward-flow units even right up into the mid 1990’s by way of my vortex design.

In ’85, I installed a large concrete system at Infiltration for extra sales ponds and the filter systems were made up of four upward-flow concrete chambers measuring 4’ x 4’ x 3’ deep and these were connected by wide transfer ports. The media used in the last two chambers was filter mat cartridges, heavily aerated from below. These chambers were covered with decking to allow customers to view the Koi.

I can’t recall exactly when I first noticed it but it was around the late 1990’s. The fact was that whilst the majority of the cartridge surfaces were covered in a thick brown dust, the only part of the chamber where the blue filter material could still be clearly seen was a small area right at the point where the water exited each chamber via the transfer port.

It was plain to see that the areas right next to each transfer port were the only areas getting the water flow and all other areas of the cartridges were useless simply because water was tracking directly from inlet to outlet – hence the layers of brown dust covering them produced by debris blown up by the aeration below and settling on the tops of the cartridges.

It was then that I realised for the first time just how inefficient upward-flow boxes actually were.

(For detailed explanations of this, please read ‘Flow Patterns’ on the main menu.)

The ERIC Arrived

After witnessing the success of this simple principle of ‘horizontal-flow’, I decided to look into it far more closely.

There were many problems to be rectified with the old budget filter unit, some of these were the box dimensions; managing the brushes; a total re-vamp on aeration; the best material for the biological stages; getting maximum usage of the biological surfaces etc. but I was still going to promote it with a concrete outer box.

On New Year’s Eve 2009, I came up with the term ‘Endless River In Concrete’ and abbreviated it to ERIC.

That was equally as useless, simply because of the ‘draw-angle’ required on all glass-fibre moulds whereby perfectly vertical walls cannot possibly be achieved.

ERIC Maintenance

A word here about the cleaning regimes, it is absolutely VITAL that the 4” bore line to waste is not reduced or this will severely reduce efficiency.

I have no idea why many are under the impression that the one of the greatest added ‘values’ in any ready-made filter system is the time period between discharges that is specified by the manufacturer.

Seemingly, the longer the time period, the more ‘attractive’ the system becomes?

One thing I do know is that the vast majority of filtration systems I have seen have been sadly lacking in maintenance because the initial ‘novelty-value’ has been long forgotten and replaced with a chore. No one likes ‘chores’ and, as a result, some systems – especially the large, block-built, multi chamber ones are left untouched for months whilst other systems simply overflow when clogged.

To empty large, deep filter boxes and clean them thoroughly necessitates a huge amount of water being discharged to waste and this results in the pond level dropping far lower than the pick up of the water pump. Obviously, until new water gets the level back to normal the system is shut down and these clean-outs can easily take the best part of a day to carry out.

It’s painfully understandable as to why this is looked upon as a chore and I also understand why the owners are very reluctant to do this with any regularity.

The truth is, all pond filters are simply ‘pond lavatories’ and lavatories need to be flushed after use.

The ‘lavatories’ that are our pond filters are in the ‘ENGAGED’ position from the moment the water pump is switched on and from that moment they are in a constant state of deterioration. This is the reason I strongly recommend that all my units are completely discharged to waste every 24 hours – although it is virtually impossible to ‘block’ them by leaving them without attention.

If ANY water should be dumped daily, it is the water from the lavatory and ALL of it, not just a PART of it.

The difference with these filtration units is that, unlike any other on the market, this can be done in seconds, rather than hours, and there is really no visible drop in pond water level after the dump has taken place. This is simply because the shallow, narrow units themselves hold very little water and the 4” bore drain to waste removes it all to the sewer very quickly indeed.

I do recommend that a ‘constant trickle’ of mains water be used to replace water that has been dumped rather than ‘topping up’ the system in one hit. There is an overflow facility on all units that will handle any excess water and take it to waste.

The simple brush box holds the purpose-made filter brushes rigidly in position at all times and it’s the first time I have ever seen filter brushes used correctly as intended. In any single 24-hour period together with high stocking and feeding rates and in high water temperatures it is difficult for mechanical waste matter to go past even the first row of brushes and the daily flush removes all of that by the release of the 4” standpipe to sewer.

The main ‘secret’ behind it all is the curtain of heavy aeration by way of long, membrane diffusers that service the entire width of the boxes at specified intervals in tiny gaps before and after each biological block. The vertical ‘confusion’ produced to the horizontal-flow water passing through ensures that there are no ‘normal’ layers of water within the ‘river’ and thus, with the aid of the final circular baffle, the entire body of water travels endlessly as a ‘block’ – hence my term ‘The Endless River’.

I have often been asked as to the units that were replaced by installation of these systems,

Several other ponds have suffered water clarity and quality problems together with laborious maintenance chores with huge losses of water.

By having a squeaky-clean filter system on a daily basis, I believe that the results will be even better than the annual clean out adopted through necessity by the Japanese breeders.

If this IS the case and no hikui or shimi are produced then the conditions will not simply benefit high quality Koi, they will also benefit ALL qualities of Koi by way of producing much better water and water conditions.

I have tried to be as brief as possible without leaving anything of major importance out. If further information is required, it is far more detailed on the Eric website.

I didn’t do any blanket advertising worldwide and nor did I open a factory to make ‘em in and then pass that cost on in the end price to the customer.

Believe me, I have been there before; I have done that before and have got all the tee shirts from before.

I’ll take my chances with good old ‘word of mouth’ instead – the very best form of advertising and promotion in the world!