I'm worried...

[Kestral]

Housing
What size is your tank? 2.5 Gallons
What temperature is your tank? 75-80 degrees in winter, 80-82 degrees not in winter
Does your tank have a filter? Yes
Does your tank have an air stone or other type of aeration? No
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? Omega Betta Buffet Flakes (I tried pellets of another brand but my fish wouldn't eat them)
How often do you feed your betta fish? Twice a day

Maintenance
How often do you perform a water change? Once every two weeks and once per month
What percentage of the water do you change when you perform a water change? 50% every two weeks, 100% every month
What type of additives do you add to the water when you perform a water change? Stress coat

Water Parameters:
Have you tested your water? If so, what are the following parameters?

Ammonia:
Nitrite:
Nitrate:
pH:
Hardness:
Alkalinity:

Symptoms and Treatment
How has your betta fish's appearance changed? He has a weird almost transparent offwhiteish thing on his head... It looks like this, except only one. I also noticed, a few days ago, a lump on his side! It looks like this
How has your betta fish's behavior changed? It hasn't. He isn't lethargic. He's swimming around, pooping, eating, and flaring.
When did you start noticing the symptoms? The thing on his head I noticed a week ago. I noticed the bump a few days ago.
Have you started treating your fish? If so, how? For the thing on his head, I put him in a 1/2 gallon tank with aquarium salt. I changed the water every day and monitored his head. It seemed to disappear after about five days, so I put him back in his normal tank. Well, I realized that when I put him in the smaller tank, he lost color, so I couldn't see the thing on his head. In the small tank, his face turned grayish and his fins and body were greenish blue. In his normal tank, his face is black and his body is dark blue, his fins are red, dark blue, and slightly blueish green. I assume he likes his big tank better. After a day or two in his big tank, his colors came back and I noticed the stuff on his head again.
Does your fish have any history of being ill? No.
How old is your fish (approximately)? I don't know at all.

[ChoclateBetta]

You need more water changes and a heater.

[callistra]

You definitely need more water changes. You need at minimum 2 50% water changes a week, one including a thorough vacuuming. of the gravel to remove poo or the stir/dip method to remove poo. That's because anything less than 5 gallons is very hard to maintain a good bb supply (cycle) and a lot if not most will tell you not to even try and still do weekly 100% changes (plus the 50% mid week). Also have a drops kit for ammonia, nitrite and nitrate if you want to run a filter and not be making weekly 100% changes so you can test your water to make sure the ammonia and nitrite are at 0 and nitrates stay under 20

I would not do flakes in something so small because it will only muck up the water faster. Look for a good quality pellet where the first two or three ingredients are whole fish, not fishmeal and even worse would be wheat. New Life Spectrum Betta and Omega One Betta Buffet (they make pellets too) are two that qualify. Also make sure he's getting one fast day a week with no food.

You need a heater for the winter that will maintain the temps at stable 80 and not let it dip like that.

At this point I would do a 100% water change and rinse the gravel to remove poop that's accumulated. The filter media should be swished around and rinsed out in the old tank water to remove debris. I think you're going to need to continue to treat with AQ.. extend to 10 days this time.

Here's how to do big changes without shocking

To do a water change, use a little cup like a plastic solo cup - this cup must be only for him and have never been used with soap or other chems. Scoop him up in this cup (keep him in the cup about 1/4 full of water - it doesn't need to be much because he won't be in it for long) and leave him in the cup while you change his water. To do the 50% use a turkey baster - dedicated only to him that has never seen soap or chems - and drag it through the gravel and try to suck as much of the poop out as possible, in addition to 50% of the water. Use a thermometer under the running tap to get it to be the same temp as the water that is normally in his tank. When the thermometer says the flowing tap is the right temp, fill back up his tank. At this point, add the conditioner (dose for how much water you change - if you change half the water you add half gallon worth of conditioner, If you do a 100% water change dose for the full gallon change). Float his plastic cup with him in it in the new water. Slowly add a couple tablespoons of the new water into his cup every 10 minutes for at least an hour. Finally, dump him in gently but try to get as little of the old cup water back into the tank as possible. When you do the weekly 100% you will do mostly the same thing except empty his tank fully and rinse everything in it very well under warm water but never use soaps or chemicals. Once it's fully cleaned/rinsed you can refill it and repeat the cup/acclimate phase.

[ChoclateBetta]

NLS is a great food.

[Kestral]

Neither of my betas will eat pellets. They put it into their mouth and repeatedly spit it out until they just give up and swim away. Flakes are the only option.

[callistra]

So you've already tried omega one and new life spectrum?

[Kestral]

I haven't tried new life spectrum, but I've tried omega. My fish simply can't seem to eat the pellets.
Personally, I don't see how pellets or flakes is going to get rid of a bump and a white film thing on one of my fishes head.

The bump is the same size, but another one has appeared (I think it's been there since I noticed the first one) near the end of his body. The white on his head is getting worse/better. It looks like it spread over a larger area, but it's less white and seems to be getting better.

I'll do a 50% once a week, but I can't do any more than that: A) I don't have much time during the school year, and B) It stresses out my fish.

I would buy a heater, but they're expensive and I'm not going to buy two if I don't absolutely need them. For now, the light on their tank is fine. Where I live, the temperature changes constantly. We have random cold days, random hot days... it has been 80 degrees during the winter before, and the next day it dipped down to 40. I think a heater would be unsafe, wouldn't it? If the heater didn't turn off at night (when it gets really cold in winter) and the next day it was hot, the tanks would overheat.

I would treat him with Aquarium Salt but I did that for a week or two and nothing happened. Plus, he turns grey when he gets put in a small tank, and I won't be able to tell that it went away. D:

[Tikibirds]

Not having a heater is more unsafe because his tank water will fluctuate with the room temp. Going from warm to cold to warm will not only stress him out but it will jeperdize his immune system. Adjustable heaters will shut off once they reached the desired temp. However some of the heaters under 25 watts that are designed for bowls and smaller tanks will not automatically shut off and will continue to heat the temp till its 90 or more. This is why I suggest 25 watt adjustable heaters. He is a tropical fish, unless you live in Thailand or the Caribbean/south America - he pretty much needs to have a heater. 75 isn't horrible but he should have a stable temp between 78-82.

Omega one also has flakes, so if you have to feed flakes - feed those. They have much better ingredients then other brands

[Kestral]

Those are the flakes I currently feed him. xD

[Tikibirds]

Pellets are better, in general but for flakes - those are probably the best ones you can get. The only thing is, be careful not to feed too many flakes. it's easy to over feed them since it can be hard to grab just a flake or two but the omega ones seem alot bigger then the tetra or similar flakes. I have them too. Every now and then I will feed those for variety.

How is that white stuff on his head? I asked about it because I have one guy that has something similar that just appeared and the response was that it may be columnaris. If that is the case (which I am not positive it is but), then you will need an antibiotic to fight it - like Kannaplex, Furan 2 or Triple Sulfa. Maracyn AND Maracyn2 is also a popular combo but It never really worked for me, unless I used like 2X the recommended amount.