1. Temperature fluctuations can cause stress, and a stressed fish is more susceptible to parasites/disease, but the temperature changes do not, in of themselves cause disease.My tank fluctuates between 76.5 and 79.5 on a particular day depending on my ac use. That wouldn’t cause a problem right.
I’m trying to figure out WHY they got sick. Here are my three theories.
1.temp fluctuations
2. I accidentally fed them spoiled clams a couple times
3 random bad luck
2. The fish might not have eaten spoiled foods and if they did, they get a bad 'stomach ache' or poisoning. Like in 1. it might be a stressor.
3. Hobbyists often fall back on 'luck' when things go wrong. But I notice hobbyists never claim it is luck when all things are going well. I believe, in this hobby, we can provide the best environment for our 'inmates' and the best foods which make the fish thrive, not just survive. This isn't luck, good or bad; it is diligence, understanding/knowledge, attention to details, and work.