I moved my aquarium to a new apartment about a month ago and i just recently noticed a dark lump growing at the base of my betta's top fin. I first got him a year and a half ago. He was a centerpiece for a table at a wedding and as he had been shipped in a truck and stuck in a little bowl for hours and hours, all his fins rotted off. I bought him a new 5 gallon tank, silk plants and a filter. Soon after his fins all grew back, but are still slightly raggedy. He is still very active and eating regularly, but this lump concerns me. Any idea what it could be? How should i be treating him?
Housing
What size is your tank?
5 gallons
What temperature is your tank?
Average 72
Does your tank have a filter?
yes
Does your tank have an air stone or other type of aeration?
open top
Is your tank heated?
no
What tank mates does your betta fish live with?
none
Food
What type of food do you feed your betta fish?
pellet food
How often do you feed your betta fish?
once a day 3-5 pellets
Maintenance
How often do you perform a water change?
1-2 times a month
What percentage of the water do you change when you perform a water change?
all of it
What type of additives do you add to the water when you perform a water change?
betta bowl conditioner
Symptoms and Treatment
How has your betta fish's appearance changed?
Raggedy fins, large dark lump
How has your betta fish's behavior changed?
not at all, seems hungrier if anything
When did you start noticing the symptoms?
about a week or so ago
Have you started treating your fish? If so, how?
no
Does your fish have any history of being ill?
fin rot
How old is your fish (approximately)?
about 2 years