New Get That Water Circulating in Your Garden Koi Pond

How to Maximize Your Garden Koi Pond Turnover Rate

Simply put, the turnover rate of your pond is how fast it takes for all the water in it to go through the pond filter. It varies from pond to pond.

Ready...Set...Calculate!

This should excite you math-whizzes out there. To find out what your Koi pond's turnover rate is, simply calculate how much water your pump moves per day and divide it by the volume of your pond.

So, for instance, if you have a 50,000 liter pond and a pump that moves X liters of water per hour, it would be pumping (X*24) liters per day. Take that number and divide it by 50,000 liters and you have your turnover rate.

The turnover rate determines the average ammonia concentration in your garden Koi pond water. That's how much ammonia is left in the water after filtration. This will vary depending how often the pond water is turned over.

Why does turnover rate matter?

High turnover rates ensure high oxygen levels in the pond. You need oxygen in the water because Koi need oxygen, the plants need oxygen, and the microorganisms in the water need oxygen to live. Because of this, oxygen levels in the water tend to fluctuate depending on many factors including time of day, number of fish, number of plants, etc.

On the reverse side, low oxygen levels can spell disaster. So keep your eye on the oxygen.

Turnover Rate and Bio filters

Knowing your garden Koi pond turnover rate is also important when shopping for a bio filter. Keep in mind that a filter chamber can handle only so much. It does not have a limitless capacity. Additionally, your pond's flow rate will affect the water's residence time in the bio filter.

Residence Time?

Just like how it sounds, residence time is the maximum amount of time the pond water is in the bio filter, in contact with the bio media.

For instance, if the residence time of the filter chamber is 2 minutes, that means it takes the bio film and active bacteria in the filter 2 minutes to convert the harmful ammonia in your garden Koi pond (from the Koi feces) into nitrites and then to nitrates.

You don't really need a chemistry degree to understand this - well, on second thought, maybe you do. Point is you don't want ammonia. Ammonia makes the Koi sick. The bio filter oxidizes it and converts it to something safer for the fish.

We could go into the theories and discussions involving how these hardworking little buggers do their work, but we won't. We'll just take a moment to thank them right now....

OK.

The bottom line with bio filters is you can't have too much of it protecting your garden Koi pond keeping the water clean and healthy for you fish. Having said that, there is no reason to get all excited and begin messing around with the flow rates to try to maximize contact time with the bio filter. Leave that alone.

If turnover rate slows down, you could put your bio filter into ammonia overload. You don't want that, trust me. If your bio filter is not able to oxidize all the ammonia on the first pass, it has another opportunity the next time around providing your turnover rate is decent.

If you have a new garden Koi pond, keep in mind that it takes time to get a new bio filter to grow bio film. It took you 9 months from conception to birth (10, really) so don't rush nature. Give the little guys a chance to get going.

Let the pond find its own "happy place" or equilibrium. Don't over-feed the Koi. The more you feed, the more they excrete; and with an immature bio filter, this can lead to problems.

Keep an eye on the ammonia and nitrite levels and just let nature run its course.

Oh, alright, I'll tell you how to cheat nature. Get some Bao Bio Clear - that'll jump start the bio film growth.