So, it's been a long month. A month ago we noticed one of our younger fish (a grow out) we've had since last November losing it's coloring, both sumi and hi. We knew we had flukes at the time (scraped and found) and treated in the midst of about 16" of rain in 2 weeks time. Had our koi show in Indy, went to Jacksonville, came home and within a couple of days realized some more of our newer fish (especially our nicest fish) losing color. The main color you notice going is the hi, the sumi is somewhat faded on the fish compared to 2 months ago. At first, this had been limited to our fish we have purchased in the last year, but noticed today that fish we have had for 4 years are starting to lose their coloring.
This is what we know. Our ammonia, nitrites, nitrates are all 0. Our pH is consistent in the evening at 8.2-8.4 while in the morning we are at 8.0-8.2 consistent. Our kH is 179, our gH is 107. We haven't changed our food any and use a combination of Ray Abell's wheat germ and hi protein and Hi Silk 21. We have 12,000 gallons with a bioreactor, bead and prefilter. We have a low stocking level (but overstocked for us) of 16 fish, 6 of which are in the 7-9" range. We had a water test done 3 months ago and finally got the results a couple of weeks ago. We have .282 ppm of copper in our source water (from the water company) but in the pond it's .005 ppm. We run our source water through a water softner (typical hardness without water softner would be in 400s) and then through a small carbon filter. The water tested out of the pond with .007 ppb of lead, 5.91 ppm of magnesium, .005 ppm of manganese, .01 ppm of iron, .05 ppm of aluminum. So we know we have some metals. We are dealing with that. Just to be on safe side, sent new samples out for testing again to UGA and are waiting on test results. We have city water but the source for us is a well that was changed to a different well in early spring.
The problem is even after figuring this out and using stuff to neutralize the metals, our fish are still losing color. In June we had 22" of rain, we don't have run off, Marc sprays the yards on both side of us so we know we don't have issues with ChemLawn or anything. I know the pH has swung a little with the rain, but not a lot, maybe .01-.02 after a quick hard rain.
We don't have a large show collection and we're going to lose them all (they'll be junked for showing) if we can't figure out how to stop this. We have Marudo, Torazo, Quality Koi among others in our pond. We are parasite free (have scraped several fish a few different times). Even our goromo is losing coloring and we've had her the longest and never had issues with her coloring. Any thoughts/advice would be appreciated.