July 26, I added three newly purchased 1Ē koi to a 75 gallon tank that has four larger 4Ē koi (3 black Karasugoi & a Doitsu Taisho(mostly scaleless)). Yes, in hindsight I should have used a quarantine tank.
30% water change was done on the 27th using API Stresscoat and morning of the 28th two of the small koi had a handful of tiny white spots on their fins. I dosed the tank with non-iodized salt (tablespoon per 5 gal
as a start)
Spots were all gone the next morning, then today (July 31) the Doitsu Taisho is covered with dozens of tiny white spots. None of the others have any spots although the Karasugoi appear to have a thicker than usual slime coat.
They all have voracious appetites, no clamped fins, no flashing, no lethargy.
For some peculiar reason the Aquaclear 110 filter on this tank has always produced thousands of tiny air bubbles that stay suspended in the water for a long time before disappearing
Iíve got 60 years experience in the hobby. It has probably been 30 years since Iíve had a case of Ich, but these spots look smaller than Ich and almost look shiny rather than flat white.
Iíd love some opinions on whether these could be tiny air bubbles adhering to the slime coat, or something more serious.