Did you know that formalin knocks oxygen out of the water? This means that if you’re treating fishes that already have gill disease, it would exacerbate the condition. Always get a definitive diagnosis before reaching for the “cure all” treatment.
And For those needing to treat their fishes with formalin, now is an ideal time to do so because of the cooler weather. Cooler waters tend to carry more oxygen than when it is warm.
