Updated: 11.05.14 By admin

Q. Is it vital to discharge an Eric filter every day?

A. Not at all, the head level drop between the brush box stage and the bio stage clearly shows you when a discharge is required.

Of course this drop varies with water temperature, feeding regimes and seasonal variations when leaves can become a problem.

However, in view of the fact that time taken to discharge the unit is rapid and the water volume discharged is so low, it’s a good idea to discharge the unit regularly, if only for peace of mind.

Q. What is the life expectancy of the brush box?

A. Eric brush boxes have been in daily use for over four years and no one yet has asked for a replacement.

Q. What is the life expectancy of an eMat block?

A. Because the eMat sheets are only used as ‘surfaces’ where water is made to ‘pass by’ these surfaces as opposed to ‘passing through’ these surfaces, then the life expectancy is just about endless.

The surfaces may stain with leaf tannins and pond medications but these are harmless.

Algae stains may become an issue if the unit does not have a lid or some other form of cover.

Q. My pond allows me to install an Eric filter either pump-fed or gravity-fed, which would you recommend?

A. I’d recommend a gravity-fed unit from a bottom drain every time, simply because bottom drains allow most sizes of debris to pass through freely into the filter for discharge. Most pumps placed on the base of a pond will gradually block and thus need regular cleaning in order to maintain their output.

Q. Compared to other filtration systems the suggested flow-rates on Eric systems are low, why is this?

A. The static eMat surfaces in all Eric filters are huge when compared to the volume of water they are filtering. Pond water is induced to ‘pass by’ these static surfaces as a ‘block’.

In order for all these surfaces to have a constant flow of ammonia-laden water and for the bacteria formed on the surfaces to process it, a longer dwell-time is required – hence the slow flow-rate.

Q. You recommend a constant trickle of tap water to slowly replace water discharged in cleaning – why?

A. Yes I do strongly recommend ‘the constant trickle’ to replace discharged water on ALL filters and not just Eric filters.

However, Eric filters are only narrow and shallow affairs, which means after the unit has been completely discharged to waste, the tiny drop in pond water level allows the pump to be re-started immediately instead of having to wait for lengthy ‘top-ups’.

Most other filtration systems are too deep to allow this to take place.

Also, if there are unknown quantities of additives to mains water supplies, it is far safer to dilute this into the pond water by ‘trickle’ rather than full bore.

Q. On the larger Eric filters is it vital to have a 4” bore line to waste?

A. Originally I considered this to be of great importance because of the cleaning power of the ‘Whooosh’.

But after using my filters on my own pond for some time I now prefer a much slower discharge, simply because I find it to be far more thorough.

I have since reduced my own 4” waste outlet to 2” and my latest view is that a 4” waste is only necessary to house the standpipe and overflow to waste, after that the line can be reduced accordingly.

Q. You prefer to use brushes as your mechanical stage – why?

A. For several reasons in no particular order of importance.

Firstly, Koi pond water is filthy by nature and, irrespective of what type of mechanical stage is employed, if water can pass through – then so can some debris.

Secondly, there is no such animal as ‘a self-cleaning filter system’, if that were the case then why don’t vacuum cleaners, air-con units, oil filters and engine air filters use them?

My EPDM brush boxes show, for the very first time, how filter brushes can be used correctly.

I fully accept that, like any other mechanical stage, some debris will pass through.

But it will never be passed back into the pond because the total discharge of the unit ensures it is all taken directly back to waste.

As to other reasons, my brush boxes are cheap; they last indefinitely; they have no moving parts and nor do they incur any running costs.

Q. Why can’t I make up the inlets and outlets of an Eric filter directly to PVCu fittings?

A. The inlets and outlets of all Eric filter systems are made with polypropylene tube and this tube cannot be connected directly to PVCu tube.

In view of this, all units supplied come with the necessary rubber connectors to allow this.

Q. What happens if the waste outlet pipe is on the wrong side of the box for my installation?

A. That’s not a problem, Eric units are not governed by moulds, and you can specify where you need the waste outlet when ordering – see illustration below –


Q. What is the ideal running level of water in Eric filters?

A. Ideally and in order to get the most from the eMat blocks, the water level when running, should be 10mm above the tops of the eMat blocks.

Q. Does the latest aerated base take in waste matter when the air pump is switched off?

A. The units I use are clear units for demonstration purposes.

I’ve not exactly seen any waste matter gathering in the false base when the air pump is switched off but I have seen traces of potassium permanganate filling the gap.

So I must assume that this could and will occur.

However, once the air pump has been running again for only a few minutes, the only thing that can be seen in the base is air.

Q. You state specific water volumes that each of your Eric models can handle, are these merely numbers pulled from the air or perhaps ‘wishful thinking’?

A. These handling capacities have been detailed purely as a result of feedback from the Eric owners who use them. Please be assured that all these figures are extremely conservative.

Q. There are many different pond filtration systems on the market today; can you explain exactly why you consider Eric Filters to be unique?

A. Firstly they all adopt the horizontal-flow water principle and that alone should explain why they are unique, no other pond filter system I know of uses this method.

Multi-bays, single bays and bead filters all use the upward-flow water principle and showers use the downward-flow water principle.

However, the only way that upward-flow and downward-flow systems can possibly operate is by way of a water pump.

Eric systems also need a water pump, but this is not to make water do ‘un-natural tricks’ – it is only a method of continuing the natural flow of water that takes place in a narrow, shallow and a miserably short box.

To clarify, I use the term ‘horizontal-flow’ in order to explain to others, but if you observe our river systems, they all meander gently ‘down’ towards our estuaries.

In my filters, to address the term correctly, perhaps I should say ‘99.5% Horizontal-Flow’ because that’s much nearer the truth although few would grasp this pompous term.

And that’s the only real reason I need a pump to continue the water flow in a box with a perfectly horizontal base.

(Thinking aloud for just a moment, if you imagine a long canal with a base that’s identical throughout. Place a huge pump at one end and pump the water back to the other end, then the canal would start to move and that’s pretty close to what takes place in Eric filters.)

Now returning to Eric and the ‘Endless River’, rivers vary in depth, they twist and turn, there may well be waterfalls to contend with plus the walls and bases are strewn with all kinds of surfaces. All these surfaces are ‘biological’ in the truest sense of the word and in order to try and ‘mimic’ them by man-made methods I use heavy vertical aeration all along the horizontal-line of travel.

This, in turn, confuses the water molecules that then have to navigate the narrow channels between the static eMat sheets in the cartridge blocks on their way to the pump.

This illustration should explain it better –


It’s highly unlikely that any of these water molecules can pass through the box without contacting the surfaces.