Re-circulated pond systems used for keeping fish can become extremely filthy bodies of water if left un-checked.

The waste matter produced in these bodies of water comprises of: –

Faeces produced by the fish.

Uneaten food.

Gnat larvae.

Dead insects.

Leaves of all sizes.

Conifer needles.

Twigs.

Dust from the atmosphere.

Eventually all these are taken down to the pond base where they can build up and pollute the water if not removed regularly.

(I must point out here that the word ‘regularly’ has a shelf life and waste matter doesn’t instantly pollute the water.)

They can be removed by vacuum pump if the water is clear enough but this is a laborious task.

Generally, just as long as we realise that well-placed bottom drain/s in the initial build stage can remove this waste automatically and then take it directly into the mechanical stage of a filter system to be ‘caught/trapped’ and later to be discharged to waste, there should not be a problem.

We should all consider our mechanical filtration stages to be the ‘pond lavatory’ as this is the truth of the matter and all lavatories that are being used need regular flushing.

There are NO mechanical fishpond lavatories I know of that are fully automatic, all require a certain amount of human assistance/maintenance/intervention.

The most efficient medium one can use for this task of ‘catching/trapping’ the waste is Diatomaceous Earth powder.

Alas, this is also so efficient it will not even allow water to pass through!

After that, everything else is simply a compromise – although many degrees are in the word ‘compromise’.

Mediums and systems that trap but don’t release ALL the waste should be avoided.

Containers and mediums that can’t be permanently seen thoroughly by the human eye should also be avoided.

Mediums that trap and release ALL the waste are the best ones to pursue – just as long as we realise that all filter systems are in a constant state of decay simply by being used.

Of course, there are many different items and sizes to consider in the word ‘waste’, the above list should give an approximate indication.

For many years now I have been looking into finding the best mechanical filtration system for our filthy fishponds.

This year I have also been carrying out my own observations through testing some certain aspects of this on my own system.

In 2013, there are several different methods used to try and achieve worthwhile mechanical filtration for fishponds, the list below shows some of the more popular ones currently in use: –

Pressurised units such as bead filters and sand filters.

Vortex units.

Some other settling chambers.

Sieves.

Drum filters.

Belt filters.

Tightly packed plastic chips.

Filter brushes.

PRESSURISED UNITS.

There are many other important reasons as to why pressurised units should be avoided like the plague. Instead of naming them all, I’ll just mention that nothing can be seen by the naked eye whilst the water is passing through the entire system and very little can be seen and quantified when the units are placed in rinse, backwash and discharge mode.

VORTEX UNITS.

I invented the original vortex unit that has since been copied to death by many others. The idea behind it was that a very slow spin in a large diameter container would take the majority of incoming mechanical waste slowly down to the base cone by centripetal action where it could then be discharged to the sewer.

The diameter of my vortex unit was 54”, most of the ones available today are often less than 36” diameter (in order to save space and money, so we are told) – as a result, even with the gentlest of flow-rates the fast spin produced will allow little or no centripetal action to take place.

Please avoid vortex units, I did.

SETTLING CHAMBERS.

Large-enough settling chambers are an option to consider and do a worthy job in settling out the pond waste before the mechanically cleaner water is taken into the biological stage for processing. However, they do take up a colossal area of ground space, they cost a significant amount to build/waterproof and maintenance time takes an age – usually by siphon.

SIEVES.

Sieves have been around for some years now; the major part of these is a perforated stainless steel screen available with holes of several different-sized microns. Pond water together with waste matter is passed over the screen and much of the waste matter is stored at the base of the unit for periodic removal by man. Of course the smaller the hole sizes become, the more waste matter is collected for removal.

And conversely, the larger the holes become, the less waste matter is also collected for removal.

DRUM FILTERS.

Drum filters have also been around for some years now; these also employ perforated stainless steel screens also available, again with holes of different micron sizes and exactly the same rules apply.

The main difference between a sieve and a drum is that the sieve has to be maintained manually and costs nothing to operate whilst the drum is fully automated and does all this without the constant need for human assistance.

But it does have electricity running costs and capital purchase costs to bear in mind.

One also needs to bear in mind that the motor that drives a drum is also another part of the pond system that can eventually break down and will need new parts and a service before it can be fully rectified, simply because no motors can ever be left running forever.

However, having said all this, both sieves and drums can be an ideal choice to make – if only the waste matter produced didn’t become tiny enough to pass through the holes…….. and please be assured it does.

Again, sieves and drums are compromises to Diatomaceous Earth and if water can pass through, so can particles and these particles will build up in the next stage of filtration.

BELT FILTERS.

Belt Filters have been used in industry for decades mainly for isolating impurities in oil and cloth production. I have seen these units working and know how they work but I don’t have the qualifications to comment.

STATIC PLASTIC CHIPS.

Tightly packed static plastic chips in a perforated stainless steel colander are favoured by many today for mechanical filtration purposes. The mechanical colander is circular and placed in the centre of a circular box with a larger outer circular box intended for biological filtration. The mechanical colander is fed water and waste matter from the pond drain and the plastic chips do a worthy job in trapping/catching the waste matter.

However, it’s only a short matter of time before we see the level in the outer chamber begin to drop and the longer it’s left to do so, the more the level will drop.

This is simply because there is too much waste surrounding the chips, which results in ‘clogging’.

Servicing is said to be simple and easy and by closing the system down and directing air to the colander we can see the waste matter being taken out of the colander and then directly to waste.

Exactly how much of the waste matter IS taken out we can only judge by the variations in water levels once the system is started up again.

The only way we can check this for sure is to remove all the media from the colander, rinse it all in clean water and see what we find?

FILTER BRUSHES.

Everyone knows by now that filter brushes are useless, at least that’s been the general consensus of Koi enthusiasts for many years.

Ah, hazy visions of brushes suspended from above by dowel rods being pushed aside by incoming water currents etc. followed always by endless complaints as to how messy and difficult they are to clean.

Actually I personally recommend filter brushes as a perfect mechanical stage for any filter system but only if they are used properly and not like the nightmare scenario mentioned above.

My filter brushes are tightly tethered firmly both above and below by an outer box and recently each row of brushes have their very own outer box.

Much of the cleaning required is carried out automatically from the pressure of water behind the box and if that does not satisfy – a gentle brush will ensure the brushes are visually clean.

But of course, the brushes are not even NEARLY clean, only our eyes tell us they are.

Take one of these ‘visually clean’ brush boxes out and hose it down thoroughly over a large bowl and then witness the BLACK water that falls down below into the bowl.

Even in a perfectly designed outer box this will always take place.

Then perhaps you’ll realise that this is also the stuff that escapes all of the larger solids that are successfully trapped by sieves, drums, plastic chips and brushes and as the sizes become endlessly smaller, all these are taken into the next stage to cause serious water pollution problems eventually.

At least by regularly cleaning my brush boxes I can SEE the black water produced and STOP/RECTIFY it before it becomes a real problem – AND I can do all of this in seconds!

I could also see this with the plastic chips but only if I removed them all from the colander and rinsed them in a bowl regularly, but really who takes the time to do this?

But I can’t do that with a sieve and nor can I do that with a drum because all the potential evidence has already passed into the next stage.

And the advantages of brush boxes above ALL other fishpond mechanical stages?

How about these: –

They are painfully simple to understand – a handbook is not required.

They are basic and that’s the beauty of them.

They cost nothing to run.

They last indefinitely.

They cannot break down.

They can be seen at all times to determine if they need cleaning or not.

They do not require servicing by others.

They cost very little money in comparison to any others.

They WORK!

SUMMARY.

It is not humanly possible to find a medium or a box that can prevent all waste from filthy fishponds passing through because if water passes through then so does waste.

If any manufacturer out there advertises that their particular item DOES prevent all waste from filthy fishponds passing through, I suggest you ask said manufacturer for this in writing complete with a full money-back refund should this not be the case in practice.

And finally, after you’ve digested these texts for at least three times, please remember this –

You can’t believe ANYTHING you ‘HEAR’ and only HALF of what you ‘SEE’.

And if I’M going to believe ANYONE, I’m going to believe in…………(wait for it)……………ME!