So after losing power for a day and the water getting colder than I'd like for that time, my most active fish seems to not be feeling well. He has a history of fin biting - but this time his fins are a lot more tattered and feathery looking as if he's suffering fin rot. They don't appear to be melting per se, but I am concerned. Particularly because he's acting sad - he's not lethargic really but just not his usual opinionated self. Normally when I feed him he leaps out of the water or bites my fingers, now he just waits under the water for the food and casually eats it. He doesn't swim around with the same gusto, he now prefers to float around a little bit. Should I treat him for fin rot, since his immune system was probably weakened by the cold water? Or should I wait for a bit with him in his qt tank and see how it goes? I don't want to jump to treatment options when he could just need some time to recover. Any help would be appreciated!
What size is your tank? 20gal long divided into 4
What temperature is your tank? 79
Does your tank have a filter? yes - a sponge filter
Does your tank have an air stone or other type of aeration? no
Is your tank heated? yes
What tank mates does your betta fish live with? 3 other male bettas. (divided.)
What type of food do you feed your betta fish? omega one betta pellets - hikari bio gold pellets - occasional freeze dried bloodworms and brine shrimp.
How often do you feed your betta fish? twice a day 2-3 pellets each feeding.
How often do you perform a water change? 10% change / week, 1 50% once a month / as needed to maintain ideal parameters. I test the water at least once a week, more if there's a problem.
What percentage of the water do you change when you perform a water change?
What type of additives do you add to the water when you perform a water change? seachem prime
Have you tested your water? If so, what are the following parameters? yes, but n/a no problems present
Symptoms and Treatment
How has your betta fish's appearance changed? tattered fins, paler than normal, no stress stripes.
How has your betta fish's behavior changed? less active, but not necessarily lethargic.
When did you start noticing the symptoms? about 5 days ago
Have you started treating your fish? If so, how? qt tank with daily water changes.
Does your fish have any history of being ill? no illnesses- fin biting yes
How old is your fish (approximately)? had him for about 4 or 5 months, petsmart guy.