Blog 15/12/11

The idea behind perfect biological filtration in any box or container is to get ALL incoming ammonia-laden water to come into contact with ALL media surfaces present in the container before exiting and then continue to supply these all surfaces constantly with a steady supply of more ammonia-laden water.

Once this is achieved, the entire media surfaces will house a perfect biomass that is in a permanent state of life and death and that’s about as good as it gets.

Be under no illusion though that the dead biomass simply vanishes, it does not, so it needs to be removed in exactly the same way that mechanical debris has to be removed.

In Eric units with mature cartridge blocks, by placing a temporary barrier to block the letter box slot at the base of the transfer baffle so that any bottom debris will stay within the biological stage you will eventually start to see yellow-ish gritty deposits forming on the base of the box and this is the waste matter given off by the cartridge blocks by way of dead biomass. This has nothing at all to do with the black-ish brown mechanical waste matter entering the box from the bottom drain and is trapped by the brush box. The production of this yellow-ish gritty deposit is absolute proof that the media is alive with biomass and that the biological filter is operating exactly as intended.

However, I seriously doubt we will ever find this matter in containers that adopt other water flow patterns simply because water flow is extremely difficult to harness properly when asked to flow un-naturally either by pump or by gravity.

The vast majority of boxes used today for Koi pond filtration are upward-flow boxes that are square, rectangular or circular; some are single boxes whilst others are several boxes linked together.

I have to admit that for many years I was a serious champion of the upward-flow principle but after closely studying the dust forming on the media surfaces on many occasions I finally realised that only a very small part of the media was actually being supplied with the flow of incoming water and the vast majority of the media surfaces were simply gathering a thick brown dust that could be clearly seen. This dust would not be allowed to settle in areas where there is water movement and it is a perfect indication that there is no water flow at all in these areas. In the small areas where the dust was not seen and the media surfaces appeared to be new, this was where the incoming water was tracking to the suction inlet of the water pump or exactly around the points where the water flow was passing from chamber to chamber by gravity.

In short there was no water movement in these boxes apart from the small areas where water was tracking through to the outlet, hence the reason that no yellow-ish gritty deposits will be seen.

In downward-flow applications such as showers this is a much better method for the incoming water to come into contact with the media. However it is impossible to control with any real certainty and as certain ‘easy ways’ out of a tray become blocked then other new ‘easier ways’ are found. The more this takes place the less the usable surface areas are available for the water to contact.

In the long run it’s far simpler to let water flow as it does flow naturally instead of attempting to try and make it perform completely un-naturally and then face the consequences when the end results are not even nearly satisfactory.

This is the new EricMat block, an incredibly tiny affair with total dimensions of only 500mm x 500mm by only 190mm deep.

However, when placed in the path of a wall of water that’s heading slowly towards it and then the block of water is buffeted by vertical water turbulence just before it reaches the block, the usable surface area in respect of the biomass it supports is positively frightening.

That single block is FAR more productive than ALL of this –

Think about it!

Waddy.