I started selling ready-made Eric filters back in 2010 and a good friend insisted that each one should have its own serial number.

By matching the owner’s name to the serial number and logging it down – I would be able to keep a close record of every filter sold.

It was great advice that I should have taken but in the new-found excitement – I forgot – and the first big order that followed was for 24 x E4 units for a pond in the USA.

I have always asked Eric owners for feedback on my filters and there are just a few on here – but that’s only a small percentage of the ones that have actually been sold.

I’m assuming that all the others sold have lived up to my claims – otherwise I would have had several complaints by now?

Here are some positive testimonials regarding my filters and in recent weeks I have offered a 90-day trial period for all new sales that guarantees a full refund to anyone who is not delighted with my filters – please bear this in mind if you are considering a filter or are upgrading an existing one.

Now, I’m well aware that there are others ‘attempting’ to copy my filters and I’ll just take that as a compliment – however no one else can possibly duplicate the original – believe me!

Thanks for reading, Waddy, May 2017.

Only thing I suffered was ..’wonky’ water readings ..but still fed 8 feeds a day heavy ..koi never blinked an eyelid ..In fact they was crawling up my arm at every feed ..

I’ve never owned another filter and manufacturers say do this as usually they have you hardly feeding till (what they call) maturing the filter ..i didn’t have to do that I just turned the Eric on and fed – like it had been on years ..

In the koi world I’ve learned it’s hard to prove something.

One thing I learned though is ..that the Eric filter made me a better koi keeper ..I had no drama at all for the duration ..and once my new house is sorted and pond dug ..there’s only one filter I will use.

Mathew Grafton.

It’s a fantastic piece of Filtration and a must for any koi enthusiast. Loved the demonstration and will post a video of it running on my pond when the build is finished.

Videos can be altered, and photos can be doctored, but the Eric is truly a marvelous piece of engineering that works.

Leon Soudet.

What can’t speak can’t lie.

It was a simple foolproof demonstration.

We seen the ponds and the filters and the proof we enjoyed the visit thanks.

Tony Fannon.

It was an interesting day out. I have some minor alterations to the pipe work to plumb in and just waiting for a smaller pump to arrive.

Not a complex bit of kit and using the clear models you can see the proof of how the water passes through the filter.

Mathew Faulkner.

This filter is absolutely fantastic.

The cleaning regime takes me only a couple of minutes a day.

Once a week I hose off the brush boxes, as I’m very meticulous!

This takes a bit longer…about 5 minutes.

I also love the fact that I can see for myself if things are clean or not.

All I have to do to check is lift out the brush boxes and the E mat cartridges!

No dirt of any sort can be hidden in the filter.

My water is as clear as a bell, my readings are 0 on all accounts, with the exception of trace nitrates.

I have 22 big Koi, most of which I bought in Japan 4 years ago as Tosai.

Most of these are now well over 70 cm…a few are at 75 cm.

My pond only holds 3000 gallons of water.

My fish are healthy, happy, hungry and bursting with energy.

I wouldn’t change over to another system for anything in the world.

Susan Campbell – Montpellier, France.

Since I installed my Eric 3 filter on my 13ton pond, i was able to do regular maintenance by doing daily flushing and discharge of the Eric chamber.

The brushes are very effective In capturing waste that I seldom need to do cleaning on the bio Chamber.

Cleaning is very simple and easy can be done in around 5minutes.

As a result of being able to do daily flushing, I noticed water quality and clarity has improved, resulting in better koi appetite and movement.

I am also more aggressive in feeding now since I know the filters can handle the load. Cheers!

DT. Philippines.

We made our first koi pond in 2010. It is 13,000 liters. We were very unsure of which filter that would fit our pond. The local koi dealer had many different filters for sale.

We were most interested in Nexus that this dealer did use in their ponds.

But he would not recommend these, when there was much fuss about them.

Difficult to go away for a few days, as they often went tight because of algae etc.

He told me he would start to sell some new filter from England. The filter named Eric. We struck and ordered one of these new filters unseen? We bought an Eric 4. overkill for 13000 liters but that’s how we like it.

We did had some problems in the beginning, when we mounted a too big pump .

But after a few conversations with PW then we got track of this.

We had not at that time even the slightest knowledge about water quality. Everything, absolutely everything, had to be learned. And we still have a lot to learn?

We found, however, that we should have the fish indoors in the winter, and built a indoor pond of 6700 liters.

From England an Eric 2.5 P was ordered. Believe that this was one of the first 2.5 P that was made. This works great.

But again overkill but that’s how we like it. More water should we have in the garden, we thought, and built 2014-15 a new pond at 40,000 liters.

New orders to England.

2 pcs 4 Eric was ordered. PW was beside himself, and called us several times and would only sell us 2 pcs E2.5

More than enough he thought, then the new 2.5 had the same capacity as Eric 4?

But we insisted on buying Eric 4 this time.

These works also as expected. The last filters have 10 mm filter mats. Very (Very) overkill said PW.

So today we have 4 pieces Eric filter and we are very satisfied. The main reason why Eric filters were purchased is, usability?

I am away up to 3 weeks at a time in the summer so then I must have a filter that is easy to maintain.

Stop the pump, drain the filter, fill up the filter again, start the pump – finished work? My wife can do this if necessary – easy peasy!

Summer of 2015 we were away on vacation for 3 weeks. Not touched filters in this period. And we come home to crystal clear water and happy koi.

A trickle is on of course in the ponds 24/7

Ottar Bang


PS. May 2017 – Ottar has ordered another E3 filter for a new pond he’s building.

For some years now, I have been trialling a gravity-fed E4 filter and a gravity-fed E2.5 filter on my own outdoor pond – more recently, I have been trialling a pump-fed Compact filter on my indoor pond.

I had these three filters fabricated from clear PVCu to be able to demonstrate them to myself, others and to see if any modifications could be added to improve the performance of the units.

Many of the modifications made have been most successful but there were others made that didn’t live up to my expectations and were scrapped.

However it has been easy to see reasons for and against – especially when viewing the insides from a clear box on my own pond.

Early problems were the standpipes used – some folks had difficulty locating them easily and many ‘O’ rings had to be replaced for free. For some time now the standpipes have been replaced with valves that make discharge and re-fill rapid, more efficient and with much less labour.

By dispensing with the standpipes, the ‘IN’ and ‘OUT’ sockets on the base of the filter could also be dispensed with and now that no pipe joints are required under the filter, all units have a perfectly flat base – so they are much easier to install.

Another major leap forward has been the 10mm thick eMat sheets that allows me to get far more surfaces into a biological cartridge block. These cartridge blocks have double the surfaces that the early 19mm sheets had.

I reckon the 85% of the success enjoyed with my filters revolves around horizontal flow water and the eMat sheets.

The spin-off for this alone and the testing that followed, made it easy to see that the huge E4 unit with six 19mm cartridge blocks has no more biological capability than the new E3 unit with three 10mm cartridge blocks.

Again through continued testing of the clear units, it has easily been possible to reduce the length of all filters with no adverse effects – the spin-off here means I don’t need steel support frames – now they are lighter to transport and much lighter to carry.

One-piece lids are now supplied with all units and the pump-fed and gravity-fed models all have the same end price.

Efficient aeration has always been a problem, not just the costly PVCu pressure fittings required, but also the labour required for assembling and fitting.

The aerated base was a truly wonderful idea from Ian Miles that replaced all these pipelines, but originally there were complaints that the weld holding it in place had cracked in places and needed repair.

The weld now has been strengthened significantly and all filters today have an aerated base.

With the original filter system, to make a total clean out – it took two men two whole days to do the job every two weeks.

I do a total clean out of my system – that’s the pond and the filter – every single day and it takes me less than two minutes to complete.

Do remember it’s exactly the same 17,500-gallon pond with four bottom drains that I started up originally in 1999.

If you require sparkling water quality together with biological perfection – then why not pay me a visit and take a closer look?

Peter Waddington.

Bury, Lancashire

Having been the happy owner of an E2 unit for some years now, when I set up a smaller pond (just over two tons) I chose the Compact ERIC for two simple reasons: ease of maintenance and bio-capacity.

The gravity-fed unit was easy to install and matured surprisingly quickly. The pond was highly stocked from the get-go with 30 tosai averaging 26cm. As I use this tank for growing Koi they are fed fairly heavily and I do stick to the ‘daily dump’ – I perform this as I do the last feed of the day. The ease of this action along with the thorough clean it provides is what impresses me most about the unit.

I turn the waste valve and let the filter drain and because I like things ‘squeaky clean’ I then quickly blast the brush-box with the hose.

The whole process takes me about two minutes and thirty seconds. The reason I am such a fan of these units is that I can visibly see how clean they are both before and after maintenance has been carried out and to me this is vital, no hidden waste. I can’t think of another filter that allows this to be practical on a daily basis – and I’ve used a few!

The Bio-capacity of these units is quite simply unique and rather difficult to explain without sounding as if I’m exaggerating.

Peter uses the term ‘Koi Water’.

At first I had no idea what he meant but over time I came to appreciate that the ERIC provides exactly that and although I still don’t know exactly what ‘that’ is – I am more than happy to accept the FACT that my koi continue to thrive in water maintained by my ERIC Compact filter.

‘Give it a go.’

Liam Bessel – UK.

Many many moons ago I was looking for an explanation why my Gosanke were suffering with the dreadful disease commonly referred to as ‘Hikui’.

My search brought me on to your excellent Koikichi website (a must read for any enthusiast in my humble opinion). We got in contact and soon after we revamped my filtration system for, at that time, “unknown” system called ERIC.

Now, with some five years of track records, I would think I have a pretty good understanding how ERIC’s work and what, again in my humble opinion, produce excellent results they have produced on my ponds.

Because besides the main pond of 65tons with 4xE3, I have built a “boys” pond of 18tons for my males, over-filtered by an E4 and I’m also looking after a 32tons pond with an E3 & E4 of a nearby friend.

The previous filters on both ponds were Nexus and Beads.

Below I’m summarising the “likes” and “dislikes” of ERIC as I have experienced them and in comparison to the previous filters.

Let’s get the dislikes out of the way first:

– Steel Frames: early models had a bad coating against rust. The later model is better, but eventually it’s giving up as well. The galvanised frame on my QT E2 is still fine. Obviously this doesn’t affect performance of the filter, but it is an eyesore and just doesn’t match with a hobby where aesthetic and beauty are central.
– With our water supply, the newer PVC Air bars need maintenance in terms of de-blocking the holes every now and then. Not a big deal, but I prefer the original Air bar with a quality rubber membrane. Just “squeeze” them once in a while and they perform beautifully.

That’s about it what I don’t like and you will note that it all can be fixed easily.

Now, more important, the things that I truly like about with ERIC:

– Performance: without going into numbers, the “bio” is much stronger and better than the previous filters. And even more important, it is always stable.

– Maintenance: it is a manual system, but it’s a doodle to service within minutes. The smaller cartridge blocks, and brush box are a big improvement and the full service has become even easier.

– Stand alone system: the brush box as mechanical and the cartridge blocks as bio.

– Simple, efficient and does the trick for me.

– Fish health: probably because of the very stable water parameters the immune system of the Koi is stronger as none of the ponds have required treatment for about 3 years.

– I have added 3 Gosanke since the change to Eric and fortunately none of these have developed Hikui.

In summary I can only say that I’m very happy that I have switched to ERIC and I know my friend here feels exactly the same.

Marco, Gibraltar.

Hi Peter

Good to hear from you, I trust you and Hilary are keeping well and not forgetting your little four legged friends also. As I am not on Facebook and the forum has moved there then I don’t tend to do much online reading any longer.

My filter has now been running since August 2010, where time goes I don’t know, just that it goes far to fast. Not that I want to tempt fate but everything is going well (crossing fingers).

There is still that residue build up of grit in the filter base and it does need to be cleaned out with a hose pipe around twice a year to keep it clean and remove the residue and hose over the filter mats.

The big mats do make this awkward to manhandle when they act a bit like an accordion when you try to lift them out as they are tight to the sides of the filter.

The other thing I found was the top frame this year had a fair bit of rust really pitting the metal. This I gave a clean sanded it down and then primed and painted it so it looks like new.

I am up your way in Bury on 5 Oct so it would be nice to try to meet up for a coffee and you can tell me all about the changes you have made with the filters, if your free for a coffee and it would be nice to see your pond as the photos do look wonderful. Let me know if it is possible.

Picture of pond and a recent visit attached.

Best wishes


I have been involved in the hobby over 30 years as a hobbyist and over the past 20 years in the trade.

As a dealer and keeper of high value Koi I know the importance of maintaining their health and vitality both through correct feeding and filter maintenance.

The main points I look for in a filter are :-

Ease of maintenance

Wastage of pond water during cleaning

Time taken to clean

Visual inspection that waste is removed from all parts of the filter

No expensive parts to fail

There is only one filter on the market today that can tick all these boxes, that is the ERIC.

I currently run 2 different models and both have been deliberately under sized for the ponds and stocking rates to put the filter through its paces.

Since installation on my ponds nearly 2 years ago the Koi have shown better appetite and better condition in body, size and skin.

I have replaced many customers’ filters from under achieving, hard to maintain systems too much smaller and cheaper ERIC units.

In all cases the Koi have improved and the customer is a lot happier with the ease and speed at which the ERIC is cleaned, many hobbyists partners have even taken on the cleaning due to its ‘Simplicity’ to maintain.

I would not recommend any other filter.

Matt Cameron


PS. April 2017 – Matt has just installed another Eric filter.

Peter, Thank you for a wonderfully designed product.

The ease of installation and operation makes the koi hobby pop for me.

Two things that I have learned from now being an owner of this product are, flush the toilet, and most important track me if you can.

All the obvious parts that make this filter great, people spend way too much time complaining.

Many benefits I could list do not have to be hashed.

The two do – tracking in a filter is the most important aspect.

If a filter cannot filter all the water through it what good is it?

If you cannot clean it easily what good is it?

Call me a simple man, but I have spent too much time cleaning bad filters I will be sending pictures soon.

Cannot wait for time to pass, for I am sure my assessment will not differ.

Thank you for a brilliantly designed filter.

Yes, there’s no tracking in my filters and every drop of water passing through MUST come into contact with all media surfaces as it travels along, the media surfaces are so colossal – you don’t need to mature them.

Dump/clean the filter completely to waste and you’ll hardly be able to detect a drop in pond water level – so you can re-start the pump immediately.

Best regards

Charlie, USA.

I finished building my new 20.000 liter koi pond in October 2014 with a vortex+4 chamber filter.

You know, the green polyester ones.

Starting up the pond in the beginning of 2015 gave me a lot of problems.

All the parasites paid the koi a visit.

After getting rid of the parasites and cleaning the filter I had some bacterial problems in the pond as well and lost 2 koi.

After that it went fine for the rest of the year – no more problems.

I flushed the drain twice a week and cleaned the vortex twice a week in the summer time.

Cleaning the brushes with the garden hose was not my favorite thing.

I always had to put on coveralls and my face was always covered with freckles of koi crap after the job.

Besides that, I flushed the other 4 chambers every other week. You would not believe how much crap gathered in the base and corners of these chambers.

Time bombs of bacteria waiting to go off and give me misery.

I was looking for a better and easier way to maintain a koi pond.

I don’t want a drum filter because there’s to much mechanical stuff that can break.

I like to stay as close to nature with the filter system as I can be.

First I thought about installing 2 big vortices.

But then I needed more space.

Then I found the Eric Filter website and I read almost every page on there.

And I thought that’s it!!!

By coincidence I heard that a dutch koi dealer who bought an Eric 2 and 3 filter in 2013, was selling both of them.

So I went there asap to close a deal and bought both filters for a very good price.

So on November the 4th 2015 my dad and I took the old filter out and installed the Eric 3 within 6 hours time and started the pump with a 7,1 m3 per hour flow (Peter’s advice) and waited.

I took water samples every other day for a droplet test plus I have a Seneye device.

NH3 was always around 0,028 (Seneye) which is next to nothing. The droplet test showed always zero.

This never changed into more and I never measured any nitrite.

Nitrate was always within limits so all good. Even though I was still feeding the koi 3 to 4 times a day.

In fact the NH3 got less and less as time went on and the water stayed crystal clear. I can always see the bottom drain on 1,85 meter depth.

Peter told me to ignore all water readings and just pay attention to the behavior of the koi. So I did.

The koi were overactive all day and kept eating all day.

I am truly impressed with the filter and I’m really glad I changed the old filter for a Eric 3.

In fact I’m so impressed that I ordered a Compact Eric filter for my 2000 liter indoor pond as well.

I can’t wait for it to arrive and get it up and running and ridiculously start feeding the koi that stay indoors for the winter time.

Most of all I truly enjoy flushing the filter without having to put a coverall on. So easy!!

I flush the drain 2x a week and I flush the filter once a week now.

No more shit freckles and perfect water with happy koi!!!

Complex simplicity indeed!

Many thanks Peter!!

Ramon Amsterdam.

I have a 2,000-gallon Koi pond filtered by an Eric 2.

The water quality and clarity is amazing – have never seen my pond looking so good.

It’s been running for 4 months now and the fish are so lively and feed up to 8 times a day, which they never did before.

Can see right to the bottom all the time, which previously could only be achieved from doing an annual pond clean and that would only last four weeks.

But the best thing about the Eric filter is the short time that’s needed to clean it. This is good as I’m disabled after having a leg amputated and it only takes 5 minutes or so.

Some days I can’t wear my false leg so my 15 year-old daughter will do it for me.

It’s that easy, she wouldn’t go anywhere near my old filter as it was too dirty in her words.

One word for this filter is AWESOME – thank you so much Peter.

Darren Gilligan, Shipley, Yorkshire.

“Peter, It has been some period of time since we have communicated.

Thought I would give you a shout about the Eric on my pond.

The pond is in great shape. The fish are happy and the pond has been very simple to maintain.

I must admit, I was nervous how this filter was going to work.

Looking for information about the hobby can lead to unfortunate information.

I have watched your website for some time. I have read about you in books and various sites.

You make the hobby simply enjoyable.

I may never be detailed as to knowing all the science but I do not need to know.
You have done this for me.

When I go to the pond I think about the beauty before me. That’s what it’s really about for me.

I appreciate all the work you have done to make this fun again.

The Eric has been running since March without flaw.

My fish and I say Thank you”.

California, USA.

The horizontal filter system as described by Peter Waddington I have found after over forty years a koi keeper is absolutely the best way of filtering our Koi ponds.

George Nesfield.

I did not back off the feeding or increase air to the pond or change the water all day every day, the Koi did not ask to leave the pond or die or gasp for air`in fact i now charge them rent lol for the quality of the water, the clarity of the water is gin clear better then what comes out the tap and i actually look forward to cleaning my Eric out which is stupidly easy even with the bloody blanket weed on full song .

In fact the Eric has done exactly what you said it would do the readings went up on the water at first but the koi were fine the readings are better now than I have ever had , and before you ask NO YOU CAN NOT HAVE MY ERIC BACK SOD OFF and thanks Peter for telling me the truth about how to filter a Koi pond.

George Hawk.

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