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 is rather true - to an extent.


Virtually every day I worked as a koi dealer I would speak with koi keepers who simply didn’t know how look after their water. The result, health problems and/or loss of condition. When I quizzed them the responses were always the same:


‘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.’


All Lies

The majority of koi keepers are over stocked, under filtered, feed excessively and don't maintain their systems properly.


That might sound like an over exaggeration, but my experience says otherwise. If you are 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. After a period of time you’ll develop the priceless skill of keeping your water, but this is something only experience can buy.


The key is regular maintenance. 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 and eases the load on our biological filtration allowing it to perform properly. Less organic waste within the pond gives your water that ‘fresh look,’ that 'sparkle' - and the koi will love it too.

Not All Filters Are Made Equal

In this day and age drum filters are the King of mechanical filtration. They automatically clean themselves, taking waste particles out of the water on a regular basis, the result - sparkling water. To some degree they are maintenance free. However, even with the drum filter I would recommend a weekly check and clean of the inside waste tray and any dead spots there might be. Also keep in mind that ideally even with a drum running high flow rates, the option to purge your drain lines is always a bonus. 


So You Don't Have a Drum

You can still keep koi successfully without the need of a drum filter. If you have a filter that requires manual maintenance, it is important to clean the mechanical stage as often as your schedule allows. 


Flush the waste away - the longer it's in the filter the more harm it can potentially cause.


Some koi keepers will protest that they can leave their filters for weeks and even months on end without requiring maintenance. I'm not saying that you can't get away with this but it's certainly not a risk I would like to take. The potential for problems with this method, is huge.


My experience tells me that every filter performs better if you clean the mechanical stage regularly. The more often the better. This way you avoid the inevitable 'ticking time bomb' of a neglected filter. Don’t forget that this flushing of waste also encourages healthy water changes, although every koi keeper should consider adopting the ‘trickle in’ method. However, 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. This can be true of old 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. If this is not possible I would consider modifying/upgrading the filter so that the process is made simple and quick. It will pay for itself in the long run to have a happy healthy koi pond that is easy to keep in peak condition.

What's Good?

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 maintenance to take place.


In my experience of testing many filters over the years, the following units offer this, in no particular order:

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

Two 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. 

The way I see it, if your mechanical filter is simple and quick to clean, you will be more inclined to maintain it. For instance I ran an Easy Pod as mechanical filtration and a bakki shower as added biological on a heavily stocked sales pond, 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?

It’s all about compromise, drum filters obviously 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 the easier that is, the better. 

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