I'm in desparate need of help with my betta...**UPDATE**

[My Peanuts]

You should get fresh water aquarium salt and introduce it slowly for the first time. Also look into Pimafix and Melafix, I forget which one is for fin rot. It's awesome stuff and it's not hard on their little bodies.

[BC_MoM]

Many would be against what I'm going to say, but I'll say it anyway - don't change his water so often. It could be stressing him out. I've left my guy for weeks without changing his water and he's healthy as can be. They don't get their water cleaned when they're out in Asia.

[Christmas_Hamster]

Don't do 100% water changes just do a 30% changes a day it won't be as stressful and it will keep the water clean.

[Zippy]

You might not want to move him to a bigger tank if he is already stressed moving him to a new home would put more stress on Rio.

[Alysser]

Too tell you the truth I clean his tank regularly every 2 weeks, but lately its been very dirty that I couldn't even see him. I will definately take your advice, thank you all! We'll be going to PETCO soon to pick up the antibiotics, freshwater salt, and a bigger tank.

[IRescue452]

Please don't stop cleaning his tank. I really stress that you should get a master test kit to test the water for ammonia, nitrites, and nitrates. These are all toxins found in tanks, and build up when the tank is uncycled. Also, be careful when you mix medications, this can have harmful effects. The best cure for anything a fish has is clean water and a little plain (non-iodized, non-anticaking) salt or salt specialized for freshwater aquariums. When you use antibiotics and antifungal medication you need to change the water more often. The medications kill the beneficial bacteria as well as the harmful bacteria in the tank.
BC_mom: in natural water, there are cycling agents that reduce ammonia and nitrogens. The water is changed through natural processes such as the billions of bacteria that turn the ammonia into nitrites, other species of bacteria that use the nitrites and produce nitrates, and plants that take in the nitrates. In a tank setting, the humans have to foster the growth of this bacteria, and these medications kill it off. Keep in mind also that in the wild, bettas have thousands of gallons of naturally cycled water on a regular basis.

[binka_nugget]

For fin rot, I absolutely would stick with regular 100% water changes. I've had hundreds of bettas in my care and honestly.. the only thing that took care of fin rot for my fishes were regular WCs & a bit of aquarium salt. I tried Melafix (bettafix is the diluted "betta" version) and didn't really notice a difference.

If it was stress related, you'd notice bitten fins instead of rotting fins. If that's the case, then I would find another way to do WCs (but clean water is still crucial to healing fins).. in stress related cases, I syphon the water out.

About his behavior though.. most bettas are fairly old by the time they get to pet stores. He has to be 2+ now so he may just be showing his age.