Two of my five neon tetras seem to be fading in color, especially the red. They are becoming pale and whitish, but seem to act otherwise normally. I found this closed thread that has me a bit worried: https://www.fishlore.com/fishforum/freshwater-fish-disease/42809-neon-tetra-disease.html I notice that on occasion, one of the fading neons is not schooling, but then he joins the others on and off. They all eat, swim, act normal. The tank is fairly new, and I did a fish-in cycle that I wish I hadn't. (See https://www.fishlore.com/fishforum/aquarium-nitrogen-cycle/116119-cycling-fish-wish-i-hadnt.html ) Now my ammonia levels are very low, bouncing between zero and .25 ppm. But my Nitrites and Nitrates are at zero as well, so I am not 100% sure it is completely cycled. The ammonia spontaneously fell to zero, not as the result of a water change. and only rarely in the last few days have I seen any color off yellow. But still no sign of Nitrites or Nitrates. My tank is a 25 gallon acrylic 36" x 10" x 16" high. Filtration is HOB Aquaclear 50. Temp running about 80f and pH 7.2-7.6. One cory cat is the only tank mate of the 5 neons, save for a couple baby snails that hitchhiked in on a bunch of elodea. Any advice is welcome. THANKS!