Hello! I have a 15 gallon tank with 6 Glo Tetras. I cycled the tank for about 1.5 months and added the fish when the water was ready. After a few days, I noticed white spots on 1 fish, then more the following day. Treated the tank for Ich and all the spots are gone. Now I’m dealing with a nitrite spike. Nitrites were around 1-2 ppm and nitrates were at about 20ppm. I did a 50% water change and brought the nitrites down to about .25-.50ppm. I also added some aquarium salt and healthy bacteria. Do I continue to do water changes and if yes, how much? The smallest fish seems stressed. He’s hanging out at the top and swimming erratically.