2 Gallon Tank Allergic Betta?

I recently switched my male betta's food from Wardley betta pellets to Aqueon betta pellets. He wasn't eating the Wardley, but is now mowchowing on the Aqueon stuff. But within the last couple days, his eyes, mouth, and gills seem red and irritated? Could it be an allergy to the new food that is causing this? I did do a full strip down on his tank, rinsed the gravel and plants, and replaced the water from the excess food build-up, treated the water, etc. There was a food build-up from him not eating, and I had no gravel vac. at the time. I can't get a picture just yet, my camera is not working

Edit- his tank is a 2.5 gal. for now

 

I've never heard of a fish having an allergy. 2.5 is small for a betta; have you tested the water recently? It sounds like it could be ammonia burns, especially if you cleaned all the surfaces in the tank - perhaps you're going through a mini-cycle.

 

I didn't scrub anything down, just rinsed it all, didn't change the filter, and left him in a holding container for 24 hours. He was fine the entire time. It was also pretreated water before I put it in the tank. I agree its small, but he was supposed to be a she to add color to a community tank. But when his fins unfolded and the current sent him tworling around, the 2.5gal was just quick thinking

 

Ohh I see. That's unfortunate. Can you test the water? Also, did you rinse everything in tank water, or tap water?

 

I can test everything but the ammonia. It was tap.water. But when I put it back together, I put his gravel and decor.back in, then added the treated water, and let it sit for 24hr(with the filter running)

 

I'm not sure if it would be enough to cause a mini-cycle, but usually it is advised to rinse decorations and cruddy filters in tank water, because if you rinse them in chlorinated tap water, then you may be compromising the bacteria.

That's unfortunate you can't test for ammonia. If it is within your means to purchase a test, especially the API freshwater master test kit, I definitely would. There's a chance that the ammonia levels are high, which may be causing ammonia burns, but there's no way to tell if you can't test! I also always recommend testing the tap water; I found out that mine has 0.25ppm ammonia in it, so my daily water changes were doing more harm than good.

Also, if you can upload a picture I'm sure that would help more experienced members with diagnoses.

 

Camera's still broken, but the coloring is leaving. The redness is so much better.

 

Did you switch back to the old food? If you did, and he started getting better, maybe you were right! You could then test your hypothesis by switching to the new food (that he's possible allergic to); if he gets worse again, then you know it's the food.

 

I tried to switch back, but he's hooked on the new food, lol. He is quite a greedy little piggy.

 

Chances are that because the fish is eating more, you are feeding more, and you overloaded the filter. It sounds like you probably just had a minI cycle while the bacteria caught up to the increased bioload.

 

He used to get 3 pellets twice a day, except Sundays. That's the diet all my betta's get, just seems to work for them. When he stopped eating altogether and started ignoring the food, I bought the much smaller pellets, so I try to give him the same amount as if he was on the other food. Now he just attacks it all as if it was his last meal. But I never feed him more than I used to