He's pooping but not eating

He stopped eating last year November, I wasn't too worried because a lot of people said their balls go on hunger strikes. But lately I'm worried because he poops, and is active like normal(when he was eating), but his pe has a wierd brownish color, and he doesn't eat. He just looks at it, and even goes nose to nose with it but doesn't strike. I'm not doing anything different than before the fast, should I just wait it out? Or should I take him to the vet to get checked? This was my first winter with him, so I'm really starting to worry.

about how old is he? Is he loosing weight? What is your setup like?

If all other husbandry practices are good (i.e. temps, room, humidity etc.) I would look at the proximity of windows. I live in Montana and my tanks are pretty close to the windows, and I have noticed that the hunger strikes are related to when the days get shorted. That ambient light makes a huge difference. I moved them downstairs to a room with no outside light sources and feeds started becoming regular again.

Bloodsong

I think he's about 3~4 years old, not losing weight, and I use a tub.
Husbandry practices are the same, yea so I guess it might be the window thing, thanks a lot!