Nitrogen in the water can be bad. Nitrogen in the potting substrate
can be good. Balancing the two is the trick. You might try
removing nitrogen-hungry potted plants (yellow leaves) from the pond,
inserting fertilizer tabs into the substrates, place in a bucket and
flush several times (fill the bucket, let it set for an hour or so,
empty the bucket, refill, etc.) , then return to the pond. This will
put nitrogen where needed and reduce overloading the pond. When
fertilized in-pond, much of the fertilizer winds up where it is
unwanted: in the water itself.

"Just Me \"Koi\"" wrote:

Isn't nitrogen, nitrate, and nitrite the things we spend so much money and
effort in trying to remove from the water?

I am soooooooo confused!