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Keep It Simple

"Look after your water and the koi will look after themselves"


I don’t know where I first heard this saying but it does ring true.

Modern Trends

Even with information being more accessible than ever, many koi keepers (especially those new to the hobby) lack a basic understanding of how to keep healthy water. This is probably because 'water keeping' and 'pond husbandry' isn't the most glamorous of topics and even when they are discussed, the focus is usually on gadgetry and funny looking figures, which only aids in alienating the masses. 

I'm not saying that getting into the technicalities of water behaviour and manipulation isn't worthwhile, because indeed it is, dependant on your goal. However, I do think that with the recent influx of YouTube celebs focussing on these subjects, the wider audience (which is predominantly made up of 'average koi-keepers') are over-looking the importance and understanding of looking after the 'nuts and bolts.' This is because these 'basic' things are considered a wee bit boring. 

Here's a little anecdote. I trained in the martial art Wing Chun for quite a few years, there was a senior instructor at my class that I learned to have a great deal respect for. When his peers were thrashing about, training the more flowery moves, he could always be seen training the boring basics. When I started training, I always wondered why and how this guy could be an instructor because I never saw him train anything else! The first time I 'rolled' with this chap, even though I was still a novice, I could instantly feel that his structure, his positioning and his angles were all unfathomably superior to anyone else I had linked up with. He was formidable, I could never find an opening. I asked how this level of skill was possible and he told me... 


"Always drill the basics, they're the key to everything else."


I'm pretty sure that statement applies to any sport or skill one can learn in life, but seeing as human nature is to constantly desire 'more' very few ever achieve greatness because almost non of us have the capacity or drive to focus on the necessary, the boring stuff. If you want to keep koi successfully, no matter the level, you must understand the importance of maintaining healthy water, there is no cheat code, fail at it and the koi will tell you. This education is a necessity, you made the choice to own an animal and you owe it to that animal to provide proper care - even though they're "just fish."


Oh christ, not another anecdote...

When I worked as a koi dealer, much like 'Groundhog Day,' I would endlessly re-live the seemingly limitless amount of koi keepers and their barrage of concerns about the behaviour or condition of their koi and the shoddy condition of their pond water. Bracing myself and knowing full well the reply to my question, long before I've even asked it... I would delicately say... "what are your water parameters like?' The following reply would be fired, well before I've even had chance to finish my sentence...


‘Perfect mate’

At this point my life-force would drain substantially! I'm faced with two problems, someone who clearly doesn't know their water parameters and the very difficult task of convincing someone that cleaning their filters once a month is not going to cut the mustard. Such was my koi dealing life. Other statements that would trigger teeth grinding and eye-twitching were:

‘I tested my water, it’s all spot on’

‘I clean my filters regularly’

‘I don’t feed too much’

‘I don’t have a lot of koi.’

I'm being facetious, but reality dictates that the majority of 'average' koi keepers don't understand the correlation between poor pond husbandry and the poor health and condition of their koi. Some might make the argument that most koi keepers don't have the appropriate filtration equipment and although I follow the train of thought, my experience tells me that most filtration works - IF you're prepared to do the maintenance. Therefore, although better equipment will always help, much like my Wing Chun instructor, it always comes down to the understanding and execution of the basic requirements. I'm convinced that the consequences felt by the lack of this understanding drives many new-comers to give up the hobby all together.


And We Can't Have That!



Reassuringly, this is a relatively easy fix and this article aims to point those koi keepers (to which the above sounds familiar) in the right direction...


King Drum

Let's start by addressing the elephant in the room. In this day and age drum filters are the King of mechanical koi pond filtration. Why? Because they automatically clean themselves in accordance with the demand placed upon them. They take solid waste particles out of the water on a regular basis, resulting in clean water and a lightened load on the biological filter media. Correctly installed, they pretty much guarantee to make the life of a koi keeper much easier.

However, they are not maintenance free and although that might be obvious to some, it's easy to forget that new-comers take the lead of more experienced hobbyists, they buy these units and forget the need to clean waste shoots regularly, or utilise every inlet to ensure waste build up doesn't occur. Or even worse, fail to install purging points and run incorrect flow rates. All these 'little details' are overlooked in our glossy content of late and all of them will contribute to serious problems if not rectified or managed. 


But what if you're one of the many koi keepers that don't run a drum filter, is there still hope?


Of course there is!


The key to creating healthy pond water in a drum-less system, is regular maintenance. The good news is that adopting a more effective maintenance regime is something that every hobbyist can do. It also doesn't cost a penny! 

So what are we aiming for...


In my opinion we must keep our mechanical filtration as clean as possible, our drain lines as clean as possible and in a pump-fed system, the bottom of the pond as clean as possible. This keeps solid waste from turning 'sour' over an extended period, eases the load on our biological filtration allowing it to perform more effectively and ultimately makes for healthier water. This is all very achievable and though your hobby will inevitably become more 'hands-on,' your koi will thank you for their healthier environment. 


Flush The Waste Away!



Firstly, if you're a new koi keeper or you have not yet developed a maintenance regime that runs like clockwork, it is important to test your water regularly. This is vital, it will give you immediate evidence as to whether you are keeping the system in balance. If the nitrogen cycle is successfully taking place and your basic water parameters are favourable then you are moving in the right direction. 

Next. If you have a filter that requires manual maintenance, it is important to clean the mechanical stage as often as your schedule allows. The more frequently, the better. Even if we discount such things as stocking levels, feed amount and equipment (which are indeed important) adopting a more frequent regime will only have a positive effect. You will automatically avoid the inevitable 'ticking time bomb' of a neglected filter and don’t forget that the regular flushing of waste enforces healthy water changes. (Although I would encourage every koi keeper to consider adopting the ‘trickle in’ method). 


Some koi keepers will protest that they can leave their filters for weeks and even months on end without requiring maintenance. It's a strange 'brag,' that harkens back to the olden days of koi keeping, when filters were made unbelievably huge, in the hope that you could simply forget they existed.


P.S. I'm not saying that you can't get away with this, but it's certainly not a practise I would recommend. The possibility for potential problems with this approach, are huge...

As a side note, a problem can arise if your filter is so large that when cleaning it you lose too much water from the pond in one go, effecting the running level of the system. This can be true of old large multi-bay type filters, huge vortexes or homemade block built filters. The key here is to still figure out a way of cleaning the mechanical stage as regularly as you can, which might involve a little imagination. If this is not possible I would seriously consider modifying/upgrading the filtration system so that the process is made simple and quick. It may seem frustrating and costly now, but it will pay for itself in the long run when you own a happy healthy koi pond that is easy to keep in peak condition.

The Criterion 

A good ‘manually maintained’ mechanical filter should be effective at stopping solid waste from entering the biological stage, it should be simple and quick to clean and it should require minimal water to do so, thus allowing regular maintenanc to take place.


don't sell filters and there are many options and brands available but some useful units from my personal experiences are:

1. Sieves
3. Nexus Units (Tempests, Eazy Pod, 220, 320) 

Some of the above combine mechanical and biological filtration in one unit, which is rather handy. A sieve however, must be followed by some form of biological filter to make an effective filtration system for a koi pond. What all of the units have in common is that the 'mechanical stage' is relatively small and can be easily cleaned and dumped to waste. Bonus. 

The way I see it, if your mechanical filter is simple and quick to clean, you will be more inclined to regularly maintain it.


For instance, when I worked in the trade, I ran an Easy Pod as mechanical filtration and a bakki shower as added biological on a heavily stocked growing system. Every morning as I fed the koi, I cleaned the Eazy Pod. By the time I had finished feeding the koi and giving them a quick look over, the filter was ready to switch back on. Simple. Now this might be seen as excessive for a hobbyists pond, but the koi were always in great health, great condition, the water always looked wonderfully healthy and I could also feed well too. So was it really excessive?

Let's remember the reason why the drum filter reigns supreme, because it REGULARLY cleans itself, removing organic waste from the pond... the 'bad stuff' is given very little time to go 'sour.' Adapt this logic to manually maintained filters and positive things will happen. Betcha! 


It’s all about compromise, drum filters offer a great solution to heavily reduce maintenance in the koi hobby. However, if a drum filter isn't an option, you can still keep your pond working at an optimal level, if you’re prepared to do the maintenance and common sense would say, the easier that is for you - the better. 

If after reading this you think adapting your maintenance regime won't be possible, due to insufficient time or what have you, then perhaps you should consider spending this years koi budget on upgrading the filtration system, food for thought...  

So confess, how often do you clean your mechanical filtration?!

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