Based on your description, I would say he has swim bladder disease. The treatment that I have read about is to do an epsom salt treatment. Basically, premix 1tsp/gallon of epsom salt with dechlorinated water in a separate container until the salt dissolves. It is good you separated them for ease of treatment. Do a 100% water change everyday using your premixed water for 10 days.
It would be best if you could get some sort of heater to get his temperature up to at least 76 degrees. You can even use a heating pad on the lowest setting with some blankets or towels between the pad and fish tank. You would just need to monitor the temperature.
I hope he gets better and welcome to the forum!!
Thanks!! I can't believe how calming they can be. Wouldn't have ever figured it. But they are. We're gettin' the tanks tomorrow along with all the accessories (heater, filter, cute little decorations...lol) I'm hooked now. Told the hubs I wanted this and he said, "I knew you couldn't NOT love them"...hehe. Thanks again everyone!
Try doing daily 100% water change at Rainbow for now, people say to put some salt thing, but that's for experts to say.
Try to take a picture for us of him, maybe you are missing something on him that we can spot right on!
Let's get this baby up and running! XD!
Also, I don't think flakes is a good food, I use mini granules for my betta because somehow they are always out of proper betta granules at my local pet store, but my betta love those mini things, haha, and I also use frozen blood worms as a treat, he loves those (now he does!).
edit: oh sheep I took 10 mins to reply and tons of ppl replied in front of me haha.
I was just fixin' to ask if I should do the the salt for BOTH fish or just for Rainbow? Betta is acting fine, fiesty as ever, so I don't want to do the salt if it might change that. I do have a couple of pictures in an album on here, but I'm not sure how to post them here. I thought the food was sucky too. They don't seem to like it a lot, so I'll check into the other kind. Thank you again!!!
Welcome to the forum and sorry you are having so much trouble with your first Bettas...they really are easy to care for once you have the right information and setups....you have been given some good advice already so I won't go into much more other than your thoughts of getting two different tanks for them is a great idea...it will make things much easier on both you and your Bettas.....
Get some Epsom salt and start the fella with the buoyancy problem on that treatment and he should be good as new in no time...
You can usually find Epsom salt at most stores that have a pharmacy dept..its cheap and a good product to have on hand along with aquarium salt, clean bucket, dechlorinator, thermometer to use in the tank and to use for water changes...its important to try and keep the new dechlorinated water for water changes within a couple of degrees between new and old water to prevent water temp issue....keep us posted and ask all the question you need we are all here to help.......