| Ok, I will be the one to break the peace and tranquility of the beautiful Sunday morning by touching the 'third rail' of water gardening--- No plants in a koi pond! Just like we have no gravel in koi ponds, the scale of koi in a closed system does not make for a healthy environment. The simplest way to cut to the chase on plants in koi ponds is to say that the premise for using plants in a koi pond is flawed.
In the majority of cases, plants are used with one of two things in mind, one) that plants make for a balanced system like in nature. And two) that plants remove nitrate do that they are a form of filtration. As I said, both there beliefs are incorrect.
A closed system in which you place an ungodly amount of fish, by body weight to water volume, can never be viewed as a 'natural system' and will NEVER work that way. Just as we have to create an artificial zone for massive bacteria proliferation, we would need to create a major plant bed ( remote) for plants to make a meaningful contribution to water quality. And even then, the massive chamber would also be adding more water , but non stockable water, to assist in the illusion that plants were a real benefit. To point #2, plants remove nitrate from water. But koi produce 10 X - 100 X what plants need in this regard. The selling point that plants are nitrate removers is they grow so well in the presence of fish nitrogenous waste. But that is a tribute to the powers of the nitrogenous waste to benefit plants- not that plants are living sponges that remove all the waste koi are producing. A simple water change will remove more nitrate, more efficiently than a section of plants will and add back more benefits than plants do in the process.
Lastly carp are not ideally found where water plants grow. They go TOO planted areas to feed and spawn but live in faster moving water situations. The best plant environment is a slow moving warm water environment. Koi like and flourish in, the opposite. Plants need shallow water, koi need deeper water. Plants like nutrient, koi need to be protected against progressive nutrification in their environment. Plants like carbon dioxide and neutral to acidic water conditions, koi like neutral to slightly alkaline systems and low carbon dioxide.
I do appreciate that a very stable water garden with a few tosai can have benefit for that stage of life. Lots of food, shade, low stress- all good. But the scale can be disrupted as the fish grow or additional individuals are added. this is a 'situation' of success and not a 'formula' for success. IMHO JR |