Testing Your Koi Pond's Water Quality

More often than not is best.

Keep a log of your test results. It can save a lot of trauma later.

You should test for the basic water quality parameters as often as possible, especially when starting up with a new Koi pond. Good test kits are available from most pet and Koi stores. Invest in a decent one and then stick to the brand to ensure consistency across all your measurements.

Test kits to avoid are these dip strips - we have found these to be wildly inaccurate. The kits that use crushed tablets are OK, but expensive relative to the reagent based test kits which use drops of reagent in a sample of water to produce a colour based reading which can be simply read off a colour coded chart. The secret to these is to read the chart outdoors in sunlight - as one of our customers pointed out the colours can vary substantially between neon lighting and sun light - and he is 100% correct in this! Good reagent test kits can do as many as 100 tests from a single box and you can generally buy the individual test kits separately. Your cost per test is thus lower, and because test kits generally do not expire it makes sense to invest in a good quality reagent test kit. 

Keep track of your tests over time. An Excel spreadsheet, or heaven forbid, a hand written diary is a vital element to Koi pond success. Your pond will establish its own set of water parameters over time that are unique to it. The actual readings themselves are not as important as a deviation from those readings! But if you do not know you pond's long term 'base line' you won't know when things have gone out of kilter.

When starting up test for ammonia, nitrite and nitrate at least once a day. Do this at the same time every day and feed your Koi at the same time every day. Feed them the same quantity and type of food consistently. Else your tests are meaningless.