Friday, June 21, 2013

Are your Koi getting sick, find out why!

Are your Koi getting sick, find out why.

Look at it this way, all filters work…they do perform a purpose that is sometimes compromised by the hobbyists or other unforeseen insults that weren’t added into the equation when setting the filter up. Each filter that we use has its limits and the hobbyist easily reaches those limits.

Back in the seventies we did experiments with under gravel filters (AKA: Bog filter in pond terminology) to see if pulling water through the substrate was better than a reverse-flow through the substrate. The theory behind the reverse-flow system by manufactures was; the substrate would stay cleaner and would prevent water channeling from detritus. As we all know, water takes the path of least resistance and when the substrate starts clogging oxygen levels in that area lessen to the point of degradation of the system.

 So we experimented with two 55-gal fish tanks and under gravel filters that were 12”X23” long times two per tank. The tanks with the reverse-flow systems; each side had 600-GPH going through each plate. That’s a lot of water going through such a small under gravel plate, plus the water was pre-filtered before going into that plate. The other tank had the under gravel filter set up the conventional way using power heads and lift tubes of 1” Dia. We ran the test for two years and at 3-month intervals we examined each tanks substrate.

What we found that no matter what direction the water flowed through the substrate they carried the same amount of detritus in the substrate whether reverse-flow are just pulling water from the top of the substrate through the bottom filter plate. The reason why this would happen eluded the manufacturers or maybe the manufacturers knew but didn’t care, the reverse-flow filters made a good selling point. Because the substrate was electrically charge and using physics the negatively charge substrates would attract the positively charge detritus no matter what way the water flowed through the under gravel plates.

For hobbyist, talking about any electrically charge substrates was never mentioned because they didn’t know. Scientists knew about water being electrically charge along with substrates that they were using. It wasn’t until the nineties that electrically charged substrates and water and air topography was even mentioned being electrically charged. To this day many hobbyists do not understand the science behind electrically charge substrates and water, or they just don’t care.

An Anoxic Filter with Water hyacinth, because Koi love to eat the roots of these plants. 

Because of this, it doesn’t matter which way the water flows through a bog filter; because if the substrate isn’t aggressively cleaned it will fill with detritus and block all chemical and biological pathways. Only in extremely fast moving or high pressure water flows that has the ability to agitated the substrate and expel any detritus will the substrate stay open to chemical and biological pathways. As we all know this just is not a feasible alternative moving thousands of pounds of gravel continuously.

I think from what I said here does explain why manufactures abandon the under gravel filter-though they still make them- for moving filters (like spinning wheels), Nexus filters (churning the filter medium) or wet dry filters instead. More oxygen and the movement of the filter medium allow the detritus to dislodge itself from the substrate or filter medium that’s being used at least in theory.

The theory is that a moving substrate will not let organics stick to it or clog it. Nevertheless, this wasn’t quite true in all filter designs, and the correct design is everything.

However, let’s don’t get mechanical filtration mixed up with biological filtration, they are two separate entities and are often mixed-up by hobbyists and one can’t tell if they are trying to mechanically filter or biologically filter with the same medium. Some organics are too complex and may take as long as a year or two for complete mineralization like tree leaves for example. Mixing the two into the same medium is old school and a standalone mechanical filtration always wins out over combination biological filters when it comes to higher redox. So very good pre-filters play the part of a mechanical filter then the biological is last. (ED: Look at Brian Woodcock’s Anoxic Filter build.) If this is not adhered to then you will have a plethora of bad bacteria where you are trying to avoid it.

Once again hobbyist will think that mixing the two is okay because; the detritus will breakdown into mulm, which is matter leftover after total mineralization has taken place, it is the simplest form of waste that is inert and will not affect water quality any longer. But once again this is not accurate, to make matter or organics into an inert substance takes a lot of oxygen and it must not compact because now the pore-water and permeability structure of the medium will change, once it compacts it then will becomes another filter medium for anaerobic biological activities to start and that means more ammonium ions back into solution.

 Only a controlled environment under Anoxic conditions will N2 (Denitrogen gas) be made and the use of Facultative anaerobic bacteria will utilize ammonia and/or nitrates as an electron excerptor. It will take the oxygen from these ions and use it. If anyone were to say they have a natural system mimicking Mother Nature then it would be the Anoxic system and no other. Natural systems make N2 that is 78% of our atmosphere. We would not be alive today if these facultative anaerobic bacteria did not do their job in such a specialized environment like natural ponds have. No N2 production then no natural system.

So for those that think forcing detritus and organics into a filter medium and it will break down to its inert substance this will become a two edge sword that will effect redox of that medium and not knowingly change the oxygen capabilities of that substrate/medium in question. This is called eutrophication or more precisely called hypertrophication, when the ponds ecosystem response to the addition of artificial or natural substances, such as nitrates and phosphates and in the worst cases more ammonia that plants love and aquatic animals hate.

In natural system this may take as long as 100 years, but in a closed system like our ponds using an incorrectly implement bog filter eutrophication may take only one year or less, there’s nothing natural about that is there? As time goes on this medium become a ticking time bomb altering pH and other parameters too and can kill and entire ponds inhabitance or make them sick from Aeromonas Bacteria that have many species causing disease in Koi. The two most common are Aeromonas hydrophila and Aeromonas salmonicida and the worst of the two is the Aeromonas hydrophila that’s the one that most hobbyists should be most concerned about. When Koi get sick, the fist thing hobbyists look for are parasites and in most cases they find none but their fish are still dying.

The telltale signs of poor water quality is; sickness will strike with sores and body abrasions not healing or ulcerations, because redox begins to drop to levels unfavorable for aquatic life. If invasive action is not taken immediately to clear chemical and biological pathways, then the pond will die. In natural systems when this happen redox can go as low as -400 mV.

However, an Anoxic system has none of these problems because pathways stay open to chemical, biological and gaseous mediators and never close. So far some biocenosis baskets that are over 20–year old now and still doing the job they were designed for…biological filtering without clogging. There’s no other filter on earth that can make the same claim, except a natural system that Mother Nature herself makes.

A newly planted up Biocenosis Basket with Zebra Rush and labeled for identification.

Anoxic Filtration Book... Still free on Apple's iBook store

No comments: