Understanding the Filtration Turnover Rate of Your Garden Koi Pond

The success of your garden Koi pond and the health of your fish depend on the strength of your filtration system.  Koi waste products are high in ammonia and if left untended and average Koi can quickly pollute a small pond to where the ammonia levels are toxic.  Keeping the levels of solid waste, ammonia, and nitrites in check is absolutely essential.

How do you do that?  By making sure that the entire contents of your pond passes through your filtration system on a regular basis.  The time in which it takes dirty water to enter the drains, pass through filtration, and come out of the return clean and fresh is called the turnover rate.

The turnover rate varies from pond to pond and is dependent on many factors including the size of your garden Koi pond, the capacity of your drain pipes, the capacity of your filtration system, the size, and health of your bio media filter, and the number of Koi you have in your pond. 

The key to figuring the ideal turnover rate for your pond is understanding the limitations of your biological filtrations system and knowing how quickly your bio media can convert ammonia into nitrite and nitrite into nitrates.  The amount of time your bio film has to do that is called the residence time, or the time the water resides within your bio media filter.  Generally, the longer your water is in contact with your bio media the better but don’t stagnate your garden Koi pond by extending your turnover rate too far.  High levels of ammonia can actually harm your bio film and decimate its ability to work properly.

It’s better to keep the water flowing.  If the bio film doesn’t do its job completely the first time around, the water will be back in contact with it in an hour or two.

Getting the proper biological filtration system up and running can be a pain.  The balance between delicate and it may take some time for you to grow a healthy bio media with sufficient bio film.  The best way to go about it is to take things slowly.  Feed your fish only the minimum recommended amount and observe.  Check the ammonia, nitrite, and nitrate level in your pond regularly, and let nature take its course.  Constantly fiddling with the chemical levels in your garden Koi pond will just make things all the more difficult.

There is a product on the market that promises to boost your bio media’s growth and support bio film growth.  It’s called Bao Bio Clear but I’ve learned that when it comes to Koi, patience is almost always rewarded.