So, I purchased my first betta 4-5 weeks ago and have run into an issue I'm puzzled by.
When I got Neo, he had a yellow-gold head and mostly turquoise fins (some parts white with a turquoise spot here or there) with some yellow/gold in them. Over the past week or two, Neo's head has started greying (it's splotchy grey right now) and his tail fin is developing a vertical white stripe just inside the edge (starting from the body and moving out, his tail fin is now turquoise most of the way, a thin area turning white, and then turquoise on the end). I'm trying to decide if he's sick or if he's marbling.
Here are the details of his environment/habits:
- alone in a 5 gallon tank with a gentle filtration system and a variety of plants (silk) and structures (to swim through/play in)
- temperature maintained at 78 degrees
- 25% water changes weekly with new water heated to 78 degrees to avoid temperature shock - stress coat added with each water change
- tests indicate a pH of 7.2, no nitrates, very minimal nitrates, very little ammonia, and hardness and alkalinity in an acceptable range
- weekly feeding schedule: 1-2 pellets twice daily for 5 days, fasted for 1 day, and fed prepared pea bits 1 day
- activity level is normal - he swims around a good part of the day and always greets me when I approach the tank.
- No symptoms of velvet or ich or other illnesses as far as I can tell.
Any ideas on what could be going on with him?