Help my Betta fish seems really sick!!!!?
Okay, well; a few days ago, I noticed that one of the Betta fish in my female community tank (her name is Royal, and she’s a blue/red/brown Betta fish) was sitting at the top of the tank, in the back left corner, not moving and just breathing a little bit. I had to go to Bible camp, so I left and came back later. I went back into my room and she was still the same way!!!! 
My Mom got a 1-gallon jar out of the basement and we filled it with water and put her in it. The fish in the OTHER tank seem fine — so I think it was just her.
I set the tank up on July 2nd and the biological filter is still establishing itself, so the pH/ammonia levels are soaring.
I have been monitoring the fish in her little jar and she has clamped fins, she’s very lethargic/not moving, and she’s NOT EATING. Royal has a bit of a red line on her side and I thought it was bacterial infection. I wanted to buy medication for it, but my Mom’s response? “How do we know it’s not something else? I’m not about to buy medication for her just to make it WORSE.”
I have put Bettafix and Big Al’s All-Purpose Water Conditioner in the tank and I think she STILL needs something.
Well, I checked some more this morning…. turns out I was right. (I think.) Royal’s red line seems to be growing. The line is just above her bottom fins and it’s bigger than last night. Do you think it could be bacterial infection?
The community tank is pretty dirty…. uneaten food and Tropica’s POOP laying around (every time I look at Tropica, she is POOPING Well, ALMOST every time) and I didn’t have time but I need to clean it soon. 
I can do that once I get home….
Metamorphic Rock, in the other tank, seems to be acting kind of funny, too…. but I can’t isolate any more than 2 fish because I only have two jars! If I have to isolate Metamorphic, I’m pretty screwed!
The other fish seem to be fine….
Also, I have been administering a 1/2 tsp of Bettafix every day to the jar. I have to clean the jar tonight, though, because I’m feeding her small portions of food and IT ALL GOES UNEATEN.
Sorry this is so long; I’m trying to rule out all the possibilities! 
Also, a side question: Is it normal for a male Betta fish to try to burrow under the rocks in his tank? Because I oftentimes hear Mr. Wimpy Fish moving the rocks in his tank. It looks like he is trying to commit suicide. XD And…. do I need to cover his tank? He hasn’t tried to jump out YET…. And during the winter, should I maybe move him to a bigger tank? Like, my extra 5-gallon one that Tropica is not using anymore? (Because she lives in the community tank now?) Because during the winter my house and the fish tanks get really cold, and you can’t heat a tank less than five gallons…. O.o;
Your fish is likely suffering from ammonia poisoning.
It is really best to fully establish your aquarium before adding fish, as the cycling process will stress them, often to death.
Since you already have fish, you’ll need to perform an immediate water change in the 25% range, and keep a vigilant eye on your water parameters as the cycle continues.
Any ammonia at all, as well as any nitrite reading, are toxic to your fish, and if they do not result in the fishes death, they will cause illness and disease.
Other stressors likely to lead to disease in tropical fish, including Bettas, include dirty water and cold. Bettas require steady temperatures of about 80. Anything colder, or fluctuating temperatures stress the fish.
I suggest that you research your sick Bettas symptoms and treat accordingly, and that you keep her in your heated 5-gallon until she is ready to re-join your sorority tank. Then use it for your single male.
You also must keep your tanks clean. If your fish are not eating the food you put in, remove it before it has a chance to soil the water. Good filtration will also help with your water quality issues, as will under stocking your tanks.
Please read this article on aquarium cycling. Without a proper cycle, you’ll never have healthy, long lived fishies.
http://www.aquaticcommunity.com/aquarium/cycling.php
Good luck.
Aquella gave a very good answer.
I, too, believe it is ammonia poisoning. This will eventually effect all of the fish in your tank, the Betta was just the first to show symptoms of it. Try and measure your ammonia. (You should also be keeping an eye on your NitrIte and NitrAte readings, as well as pH). If the ammonia is above 0.25 in the main tank, then that is almost certainly what is going on. Also, try to keep the pH down, as ammonia becomes more dangerous the higher the pH is (and also the hotter the tank). Red streaks are a symptom of ammonia poisoning, they mean that the tissue is being harmed by the ammonia. Here is a link that discusses ammonia poisoning, what is happening to the fish, and how to try and treat it: http://freshaquarium.about.com/cs/disease/p/ammoniapoison.htm You should probably be doing partial water changes in both the 1 gallon quarantine and the main tank every day to cut down ammonia. That the red streak is growing may mean that you are building up too much ammonia in the 1 gallon too, probably from left over food. If she isn’t eating, net the uneaten food, don’t just leave it in there to deteriorate and make her condition worse.
Ammonia poisoning is entirely preventable. You should have done a fishless cycle, but, as you didn’t, just take this as a lesson to do so in the future, and we won’t dwell on it now. And don’t beat yourself up over this. Everyone makes mistakes, its what you do after you’ve learned of the problem that counts.
Besides what the article mentions about the water changes, you need to clean the bottom of the tank with a gravel vacuum (the main one, the one gallon you will have to use a net, probably, because it will be too small) . Gravel vacuums are pretty cheap, you can get them at most pet stores. Siphon out all the waste at the bottom of the tank, as that will just keep worsening the ammonia problems as long as it is present, to the point that you won’t be able to save the fish if you don’t take care of that. And cut down on how much they are eating, only feed them as much as they can eat in a couple of minutes, if there is some left, take out a net and fish the food out. That will go a long way in keeping the ammonia down. The article mentioned adding in some things for making the ammonia less dangerous, I believe. The best of these products is ammo chips, I suggest that is the one you get. Keep doing daily water changes until the tank is cycled (ammonia 0, nitrIte 0, nitrAtes low). After that, you can go down to siphoning the bottom and doing a partial water change once a week. I hope you were able to catch this soon enough to save at least some of your fish. Best of luck to all of you! By the way, you have an empty 5 gallon. You can use this as a quarantine as well.
As for the side question, no, the burrowing is not normal. I’d be concerned he might have parasites and be trying to scratch himself. Is he rubbing against other things as well? If so, I think parasites might be a safe bet. If not, keep a very close eye on him for other symptoms, and be prepared to treat. If he looks like he is just trying to move them to his liking, he may be okay. Although that isn’t really typical for Bettas to do…he may just be a bit odd. Definitely get a cover for him, Bettas are jumpers, and you don’t want to wait until after he’s jumped to get him one. If you have a spare 5 gallon (and you aren’t using it as a quarantine during this time for your other fish) you might consider starting a fishless cycle and keeping him in there permanently. He’d love the heat, not only in the winter, but all year round. Its important for fish that the water not only is warm enough, but is stable in temperature too, and heaters help achieve that.