On first fill, the drains seeped in drips on the floor and I still recall spending one bitterly cold Christmas Day of 1981 trying to address the problem by emptying the systems and re-sealing the drains with Paraflex – thankfully it worked!
Whilst all this was taking place a guy named George Hurst from south Manchester contacted me to ask if I’d care to pay him an urgent visit as he wished to show me something that may be of importance to me.
George, his wife and two sons were all avid Koi enthusiasts of the day and he was the only individual who had purchased one of my spare bottom drains.
I arrived there to find yet another Koi pond had been installed in his garden; Georges sons were not averse to rolling their sleeves up where Koi were concerned.
From memory it was a rectangular in-ground butyl pond of around 2,000? gallons, the pond base had my bottom drain installed centrally, with a large in-ground header tank outside the pond as the filter.
The filter contained pea gravel and there was a submersible pump placed centrally that took the filtered water back to the pond.
In short, a pond system design that was already widely used by others.
George pointed out to me that the system was running and asked me to watch when he turned off the pump. When the pump was switched off I noticed the water level rise in the filter box as expected when the pond is connected to the filter by a standard side feed. It did exactly the same in all sidewall connections?
George then pointed out to me that there was no sidewall feed from pond to filter and nor was there a standpipe and discharge box to take waste water to sewer – instead he’d simply connected the 4” bottom drain line directly to the filter and it was a single 2” ball valve fitted to the base of the filter that took the waste water directly to sewer.
At first it took a while for all this to register with me but soon it all seemed to fall into place and it did produce excitement and future possibilities as to what could be achieved by adopting George’s method.
The pond drain at the base of the pond would certainly be taking the majority of mechanical debris out of the pond and into the filter constantly, and this also applied to the ammonia-rich water.
In short, instead of the filter relying on a sidewall, mid water supply where most of the valuable bottom ammonia was discharged directly to waste via a standpipe, the filter was getting a constant supply of nutrients and waste 24 hours per day!
I remember driving home that day with a thousand thoughts running through my head but I don’t remember the journey – all I wished to do was to get home and find a note pad and a pencil.
In late 1982 after Infiltration had been fully open for business for six months, I introduced the first two ready-made filter systems ever fashioned from glass fibre. Both were multi-chamber ‘rise and fall’ units and both were available in 2,3 and four chambers. The cheaper units had 24” by 24” by 30” deep chambers that were simply connected to the standard pond wall feed with a 4” inlet and there were support trays included for the gravel media.
The more expensive units had chambers of five feet square by four feet deep, these included a discharge box that handled the 4” pond drains and also the 2” drains from each filter chamber. The discharge box had a 4” waste connection to be connected to the sewer.
Others immediately copied the cheaper units and derivatives of these are still available today, some later supplied them complete with Flo-Cor media rather than gravel.
In spring 1983 my second dry goods container arrived from Japan, it contained the first and only? Wakishimizu filter unit to come into the UK for testing purposes.
It also contained the first 25-kilo sacks of Zeolite stone ever to be seen in the UK as demand for this was high amongst enthusiasts.