Know your Bacteria: Nitrifying Bacteria
Nitrifying Bacteria: Are the collective term for a group of bacteria that require specific food sources and are capable of undertaking a specific chemical process. Although there are literally billions of individuals the individual bacteria form into collective populations and the most important and relevant to we Koi Keepers are Nitrosomonas and Nitrobacter. The former convert harmful ammonia to equally harmful nitrite. The latter are capable of converting the harmful Nitrite to less harmful Nitrate.
It sounds simple if you say it quickly, but the complexity of the processes are indeed one of natures finest wonders. These processes are continual and are undertaken in the engine room of our Koi systems – the filtration system. To better understand the relevance of nitrifying bacteria to we Koi keepers we want to look more at the practicalities of what they actually do and how they do it, rather than what they actually are, because the information in this resource is focussed on helping everyone do a better job not intellectualising or passing an exam. None of this information is available on google , but all of it will hopefully help you become a better Koi keeper!
The requirements of all effective filtration, in order of priority, systems are:
- Oxygen
- Calcium Carbonate
- A suitable media for the bacteria to grow on
- A food source for the bacteria
- Sufficent and appropriate flow
- Sufficient physical space
1/ Oxygen
The biggest consumers of oxygen in all Koi systems are not the Koi but the bacteria in our filtration systems. To function effectively and cover all temperature variations we have some very simple advice…use air pumps to deploy 50 litres of O2 for every 1000 gallons in your systems, 24/7 – 365 days a year!
2/ Calcium Carbonate (CaCO3)
Is an absolutely non negotiable requirement for all biological filtration systems. CaCo3 facilitates nitrification and without sufficient levels vital nitrification will simply not occur. For the purposes of Koi systems sufficient = 5˚ or 100mg/l. You can read more about this in the kH section of this resource centre. Read more about kH
NOTE: CaCO3 deficiency is especially problematic in soft water areas of the UK. You can check your levels of CaCO3 by using a kH test kit. If you choose to ignore this your systems will not operate properly and you will suffer continual problems. Fortunately there is a really quick fix to redress any deficiency in your system. Buy kH test kit and buffer.
3/ Suitable Media
In 2020 and beyond there are some amazing filtration media available. While all will make, often exaggerated claims about massive surface area, the sheer volume of organic material Koi produce mean that Koi filtration systems have very specific requirements, and most of them
render conventional aquatic media totally inappropriate. The reason for this is very simple, because in Koi systems its not the theoretical surface area thats important but the surface area that is actually available. In closed media, like expanded ceramic media designed for fish tanks etc while has a massive theoretical surface area which is great or fish tank fish, its useless for Koi simply because the theoretical surface area quickly becomes unavailable when its blocked by the sheer volume of organic waste produced by Koi.
The key to this conundrum for us, is to deploy media with Protected Surfaces. There are many but we’ll use one of the most popular – Kaldness to illustrate the point. While the total surface area isn’t anything like as large as for example ceramic fish tank media, the surface area of K1 is available because its surfaces are protected by the design and actual configuration of the media.
4/ A food source for the bacteria
This is very simple and requires very little effort from us., this is because the initial food source for nitrifying bacteria is ammonia. As ammonia is naturally produced by all Koi via respiration, excreta and urine it’s omni present in Koi systems. However, of course its not quite so simple because in this instance too much can be bad news as ammonia is highly toxic to Koi. It’s therefore important to monitor and manage it. In normal circumstances your filtration system will do that for you but that doesn’t mean you don’t need to keep a check on levels in your systems. Buy ammonia text kits.
5/ Sufficient and appropriate flow
Flow is required in all filtration systems as its the passing of oxygenated water over the filter media that stimulates and encourages the actual process of nitrification. No flow = no nitrification. In fact its worse than that because if theres no flow the nitrifying bacteria quickly start to die, and the anoxic (oxygen depleted) conditions encourage different bacteria (pathogenic bacteria) and much more damaging process called de-nitrification. The correct flow of every system is different and is determined by the size of your pond and size and type of your selected filtration systems, and is facilitated by system pump(s). As every system has specific needs, the best advise is to talk to us, and we can advise what you will need for your system.
Supplements & Starters – In terms of filtration system performance, good system maintenance and husbandry really is first order of business. However today, advanced technology has refined a range of products designed to supplement, enhance and turbo boost the performance of our filtration systems. They work by either providing additional nitrifying bacteria to supplement whats already present or by enhancing the rate or multiplication of, and/or performance of existing populations. These proprietary concoctions are numerous and widely available. The reality however is that some work better than others.
Over the years we have tried them all and here at The Oaks Koi Farm we only sell products proven to perform and actually deliver the benefits they claim. Buy beneficial bacteria
6/ Sufficient physical space
A filtration system for a pond generally consists of mechanical and biological sections. These also can be separate i.e a mechanical filter could be a stand alone drum, and the biological could be a standalone bio chamber. Or in some instances there are filters like the Eazypod, Nexus of Combi drums, that perform these two operations within one filtration unit. there are varying sizes of filtration units on the market, and it is vital that the correct option is purchased, otherwise you will encounter problems. A pond filtration system should big enough to do the job that it is asked to do, and then some. In other words you cannot over filter a Koi pond. Here at The Oaks we have many different filtration systems, fundamentally all doing the same job, but in slightly different ways.
It’s good that there are different systems on the market nowadays, and certainly ones that appeal to all budgets.
Back to the point of “sufficient space” a filtration system needs to offer enough space for the media to perform, and perform correctly. In a moving bed / fluidised bed filter, the media needs enough room to move and constantly self clean. Here at The Oaks we run many different types of filtration, all of which are over specced in terms of, two to three times the capacity of the pond in question. After all the Koi you put in your pond are going to grow substantially, and the load put on the filtration system increases day by day. Look at filtration systems we sell
