This is really an exciting photo. The pond digger has been spending a lot of time this summer manipulating the filtration system of the upper pond to get the water parameters in line. The lower pond equipped with a rotary drum filter and a rock filtration system has stayed within parameters all summer with an occasional spike in ammonia when it got a little too crowded. The upper pond’s nitrite level stubbornly refused to go to 0 ppm all summer. We did many water changes, worked on moving the water more, added more media into the moving bed filter and this past weekend, the pond digger put in a different size pipe to the top of the waterfall. I think the fact that the koi are eating a little less might be helpful but who knows. While the reading isn’t as clearly 0 ppm as the lower pond, it’s exciting to see the vial of water remain a blue tone!