The dictionary definition of homeostasis is; Homeostasis [ho″me-o-sta´sis] the tendency of biological systems to maintain relatively constant conditions in the internal environment while continuously interacting with and adjusting to changes originating within or outside the system.
But what does that really mean in practical terms for Koi Keepers? Because of the importance of this, we have developed key areas of attention and within each, we have identified things you can actually do in pursuit of your objective.
Water Quality
Koi keeping really does start and end with water quality. Most fish are sensitive to their environment, but Koi are beyond sensitive to it, their entire life and development is fundamentally determined and defined by it. This outwardly simple statement not only masks the complexity of the task at hand, but its difficulty. Fortunately in 2020 and beyond we have a much better understanding of what that actually means than we did even a decade ago. Its this understanding that we hope will help you do much better at it going forward, than we ever did accumulating it!
Know your enemy: We often hear and read references to “excellent water quality” but much less often do we get to hear about exactly what that means. In our detailed sections on water parameters, we’ve tried hard to define not only exactly what elements are important, but also what specific ranges within those elements we are aiming to achieve and maintain. By understanding those elements and ranges the objective of maintaining them is not just possible, but entirely achievable.
To summarise these are the Big Four elements and their target ranges are:
kH >100. pH in the range 7.5 to 8.0. O2 = at Saturation. Temperature range 10˚C to 25˚C.
While there are other parameters that are important, notably Nitrite, and to lesser extent ammonia, non-big four elements are all contributors to problems and solutions, and not definers. By focussing on and managing the Big Four – the absolute core vital component elements that actually determine and define our water quality, and not getting distracted by the many, but absolutely much less important others, we can not only make the challenge much more achievable, but by focusing our attention and activities on what’s really important, the total workload required is actually less. Better results and less work? … has to be worth a try right!
Not only is it worth a try…it’s tried and tested and it works! How do you know? we hear you say. Entirely reasonable question. The answer is really simple, after many years getting it wrong and making mistakes minor and serious, we’ve learnt the hard way what works and what doesn’t, and what important and what isn’t. This information resource is the embodiment of this accumulated experience, its all based on real Koi keeping and it all works! Of course, in the final analysis, its entirely up to you, if you ignore or deploy any of it!
System Design
There’s an old Koi Keeping adage that springs to mind in this context: More planning less digging. It’s difficult to emphasis how important this can be. How many Koi keeper pals do you know that are on their second, third or even fourth Koi pond? While the reasons are often initially economic with assertions like I can’t afford GRP so I’ll buy a liner, and the garden isn’t big enough for 5000 gallons, so we’ll make do with 2000, all seem entirely reasonable at the time, the reality is if you’re genuinely afflicted with the Koi bug, the reality is you are eventually going to have a fibreglass pond that’s much bigger than you ever imagined. You are going to buy that drum and Nexus 320 or combi. You are going to heat your pond and there will come a time when your absolute definitive budget limit of £200/£500/£??? is displaced as your level of appreciation, becomes the defining element in your buying choices.
When it comes to system design specification, take your time. Don’t rush and think where you want to go with your Koi keeping, not just where you are. If it comes to a choice always sacrifice quantity for quality. Better to have a 3000-gallon pond with tip top water, with the absolutely best filtration system your budget allows, rather than spending the money on a 5000-gallon pond, but with less good filtration. You will overstock your pond and the better your filtration the less of a problem this will be, and the bigger the pond the bigger the overstocking problem is likely to become, so when considered in these terms its always quality over quantity! In this context, the fact is that designing, specifying and building the very best system you possibly can for your Koi, is the ultimate in preventative Koi keeping.

Maintenance & Husbandry
Its hard to exaggerate how important this element is and there is a term that will define how good or otherwise, yours is: Discipline. While this is perhaps the least sexy of all Koi keeping activities it’s also absolutely one of the most important. Developing a maintenance routine, a regular system is the best way to make sure you have both an effective routine, and that you stick to it. Have a list and tick it off each time you’ve done it. Technology is a brilliant aid in this respect, because you can keep your records on your computer, iPad,or even phone. Wherever you keep it, do keep it, and keep to it!
Cleanliness and Water changes
When it comes to Koi cleanliness really is next to godliness. There really is no such thing as a good dirty Koi system. Organic waste is our enemy and should be treated and dealt with as such at all times. Think of organic waste as pathogen food, because that’s essentially exactly what it is. Just like cold water organic waste is bad for Koi, but there’s another couple of things you need to consider.
In addition to the direct issues it causes, organic waste blocks and clogs and reduces the vital protected surface in our filters, we work so hard to design and preserve. If you don’t deal with it it will overwhelm and it will cause problems, and ultimately translate into dead Koi.
Organic waste also has another counterintuitive ability, it’s a great absorber. It not only absorbs vital oxygen, but it absorbs any beneficial additives rendering them completely unavailable to your Koi for the job you want them to do. Furthermore, it does the same to any chemicals you may deploy. To take PP as an example. When introduced to a Koi system Potassium Permanganate (PP) first attacks and oxidises organic material. So if you have lots of organic waste in your system it’s highly likely that your well-intended dose of PP will never get to the Trichodina it was intended for, because its too busy oxidising the crap! Even if it does the Trichodina will be sheltering in the waste too, making its efficacy in their removal even less viable!
Testing
When it comes to Koi, information is power, and water testing is one such information resource that’s more valuable than most. Realistically however, most test kits provide only indicative results, rather than definitive ones. In order to transform that limitation into a potential benefit, it’s necessary to keep records. By recording test information we are able to quickly note any changes. Changes to water parameters often indicate the presence or development of problems. Using water quality reading results as a proactive tool, we can at best prevent, and at worse minimise the impact of water quality issues.
Test result information can be a useful preventative but only if we use it effectively, and the first stage of that process is to record it! This, over time, enables you to develop a water quality profile for your specific pond, by monitoring this profile we are quickly able to identify any variations, hence accessing yet another tool in our prevention armoury!
Microscopy
We have a complete section on the use of microscopes which absolutely are if you enable them to be, yet another preventative tool. While two of the macroparasites identified in our general parasites section are visible by the naked eye all the others, and all the protozoan parasites which represent 95%+ of the actual parasites you’re likely to come across are not, and the only way to, a/ know you have them in the first place, and b/ identify which – requires microscopy.
It’s important not to be intimidated by microscopes or how to use them, it’s really not so complicated, and with practice well within the abilities of most motivated Koi keepers. We’ll repeat our previously mentioned assertions that all Koi Keepers should own and know how to use a microscope. Its simply good Koi keeping practice. The simple truth is the more self-reliant we are,, the better the outcome for both us and our Koi.
The ability to identify a potential parasite problem combined with the ability to take a mucus scrape, and then effectively use a microscope and then identify which parasite is present, together represent a major preventative skill set, which will save Koi! It also has the potential to save you a lot of heartaches not to mention a boatload of cash! There’s lots of help available including us, of course. At The Oaks Koi Farm, we use microscopes as a regular part of our prevention protocol and even though most of the time our results are negative, when we do find a parasite it enables us to jump on the problem immediately and avoid a minor problem turning major, which is exactly what happens if you don’t deal with a parasite, and why we include microscopy in our prevention toolkit!
Additives
While the Koi market is riddled with lotions and potions for all manner of ailments both real and imagined, it also has some gems. The key is knowing which is which! In a nutshell, we only sell ones that we have used, and proven to work. We will be happy to discuss them with you individually, but here we wanted to highlight three in particular.
The first is our range of filter bacteria supplements. These products are excellent for use both early in the season to give systems a boost, and as part of your regular maintenance/husbandry routine, to design out the possibility of any biological deficit in your system by constantly replacing it.
The next is our range of montmorillonite clays. The day to day rough and tumble of all Koi ponds results in the consumption of many important minerals and elements that are important to the well being and development of our Koi. These include calcium and magnesium which tend to be contained in most proprietary Koi foods, but also many that don’t. Over time this can result in our Koi losing condition, often the most effective way to replace these micro-elements and nutrients is to use conditioning clays. These replenish and restore these used or missing micro-elements and have a beneficial impact on our Koi.
Finally and potentially most importantly is our unique product Genesyz. As we’ve already learned pathogenic bacteria are omnipresent in Koi ponds. We’ve also learned that its impossible to deploy chemicals capable of killing pathogens, but leaving the vital beneficial nitrifying bacteria in our filters untouched. While we don’t have a chemical to do the job we do have an alternative – Genesyz.
Widely used in food production animal bacteria management for more than thirty years Genesyz was first introduced to the Koi market in May 2000 and its been widely used ever since to remove pathogenic bacteria in Koi ponds, by starving them to death! Genesyz is 100% organic and contains zero chemicals. It works by a process called competitive exclusion. Pathogens consume a specific food source that’s different from the food consumed by Nitrifiers. Genesyz competes for the pathogens food and simply eats it all, leaving nothing for the pathogens to eat. Pathogens require a constant food source so no food – no pathogens. Like all truly great solutions it’s simple. Its also proven to work. Not magic, but science working for us, instead of against us for once!
External Indicators
While the look and quality of your Koi is important qualitatively, there’s another area where you can sneak an advantage, if you invest the time to understand it. The skin, eyes and fins of our Koi, are windows to their health. Any changes, even subtle variations like fin congestion, skin lustre dulling, foggy eyes, and dorsal fin twitching, are all potential problem indicators. By tuning in and recognising them, you can access this observational virtual x-ray, that can be another important early warning system. Of course, if your Koi are flicking and twitching it might just be early season euphoria, or a pre-spawning dance…. but it might also be Trichodina, flukes, or other parasite problems. Whatever it might or might not be, what it IS, is a red flag to check. Check the water and get your microscope out, and check for beasties!
The point is whatever is or is not, by paying attention to details like this, you have yet another pre-diagnostic resource, well you do if you know about it, and now you do!
Koi Ethology
Each and every Koi is unique. We don’t just mean physically, in fact when it comes to looking after them, their qualitative looks are perhaps the least important element of all. Koi are animals that respond to stimuli, but the fact is that they all respond differently. All Koi also have unique behavioural habits. The way they eat, swim and/or respond to their pond mates, and to even to us, are all unique behavioural traits to individual Koi. Taking the time and effort to get to know them all individually, can unlock a major health care tool, because its often the case that the first indication that there may be a problem with an individual Koi, is that it’s habits change. For some it’s going off their food, for others its isolation from the rest of the pond, and for others its sulking or a change in their orientation in the water, from subtle variation inability to maintaining swimming equilibrium, to sitting with clamped fins in the corner.
By getting to know all your Koi individually you will soon get to know their individual responses, habits and reactions, and crucially also get to know if, and when they change. While this isn’t necessarily an indication of a problem, it very much is an indicator of the need for increased vigilance. Use the time when you’re feeding your Koi or just sitting and observing, to take notice of them as individuals. This way if there’s a change in their behaviour you will spot it immediately. While often it might be nothing, or like you sometimes your Koi are just having an off day, but on the other hand, it might be a problem. The fact is that your Koi are ultimate online, real-time parasite indicators, and water quality monitors. If there’s a problem no matter how small, it’s your Koi that will know first! By tuning into them you can access a big advantage, an advantage that might just save their lives one day, so take the time – watch your Koi and learn their habits!
Information
In Koi Keeping accurate information is important, but understanding is the key to unlocking that information. One of the main reasons for this information resource, is the fact that we understand the importance of this because for years we didn’t have it! The internet has exaggerated that reality to the degree that today it’s estimated that 80%+ of the information on the internet about Koi, is either inaccurate or plain wrong! This information resource is designed to be a Koi information safe harbour, a place where serious Koi keepers can find accurate useful information, all produced by other Koi Keepers! For your part, all you have to do is… read it!