I discovered two white spots on the fins of one of my Discus. The reason was low water quality as I was abroad for 15 days and I had no one to take of water changes. I did a 50% water change when I arrived but discovered that one had spots. I raised the temperature to 30 - 31 degrees (was 29 degrees) hoping that by heat alone would not spread to the rest. I cannot afford to remove one as I have no other tanks to spare and last time I removed four of the smaller one, I ended up with all dead fish as the stress was too much for them. Do you think that by heat alone would cure it? should I use medications, maybe with a half dose? Frequent water changes will eventually be made to reduce the risk...I am planning to change water every fourth day.