So I live in Jakarta when usually the temp can get to 31°C and all my fish are used to it (Yes! Including my rosy barbs and angelfish!)
But sometimes the water is around 26°C before the ich came.
I bought a heater and aquarium salt to treat the ich and when I heat the water to 30°C, my fish swims normally and never goes up. Usually when I come to my room to study, they will go up and beg for food in normal water temperature (24-26°C) This time, no they just swim and only goes up to take an extra breath. Only my angel and goldies does that (Yes, I just realised that I'm not supposed to mix goldies with tropical fishes
Any idea what is happening with my fish when the water is cold? Perhaps an unseen or inner ich?