What size aquarium? Is it heated? Is it a filtered and established/cycled? Don't keep another male betta unless they can be seperated by a partition or in an aquarium next to it. They will fight, most likely to death or near. Popular mates are cory cats. Others are a school of 6 or more tetras, platy's, molly's. Careful of similar looking to beta fish, long colorful fins. Always have a back up plan in case you have a "very" territorial betta. Caution should be taken with mates for these type of fish.

Well it's about a 5 gallon tank, and it's not heated. It is also a cycle filter. If i get a seperater do you think I could add more fish? And if i get a female beta do you think that they will fight?

-Sarah-

Well it's about a 5 gallon tank, and it's not heated,.... if you get a 25 watt heater and maintain water temp about 76-78F your betta will probably act like its old self. Unless you live in the deep south, like Florida, a heater is necessary. Betas are tropical fish not coldwater. -It is also a cycle filter.- You have a filter, OK. But is the aquarium cycled? By cycle I am refering to the nitrogen cycle. This is where bacteria is allowed to grow in your water filter, gravel, and decor etc. that processes ammonia (toxic)excreted by fish into nitrate that is not toxic at low levels. The nitrite level is decreased by weekly or bi-weekly partial water changes (PWC). For a 5Gallon I would go with PWC 1 gallon weekly or even twice a week if necessary. I provided a link about the nitrogen cycle. Some people don't "cycle" small aquariums for bettas, just do alot of PWCs. I suggest reasearch this on the web and form your own opinion. IMO, go with the cycled aquarium. And finally don't base your decision on cycling being a PITA or just to complicated (don't take this the wrong way).---If i get a seperater do you think I could add more fish? To be blunt, no, a 5 gallon is too small for a seperator. They do sell them for that size but it will restrict too much water flow. Not worth it.-- And if i get a female beta do you think that they will fight? -- Most likely, if conditions are not ideal for breeding it is likely they will fight. Until you get a little more experience under your belt , I wouldn't try it. I have a feeling your fish would do better with a heater and "cycled" aquarium. A good idea is a low maintainance live plant like a java fern. They seem to do well in almost any aquarium conditions. The nice thing about live plants is they minimize ammonia and nitrite poisoning while the aquarium establishes a cycle. I have a feeling your betta may have ammonia poisoning along with sluggishness from too low temperature water. This is bad, and can lead to illness, parasites or death. The best thing for fish is improving water conditions. Any ???'s don't hesitate to ask. Good Luck. Oh yeah , the betta is about the limit for a 5G. Maybe an upgrade to a 10 gallon or as big as you have room/budget for.

Here is a link that might be useful: Great reference

You know, bettas in the wild are pretty solitary fish. It's us humans who start thinking they're "lonely". I think the best we can do is provide them with a clean environment and regular feedings of good food.

I've kept Bettas in 5 gallon tanks with cory cats - but depending on the betta, sometimes they will be aggressive with the cories - so you need to provide cories with a place to hide.

I've also kept multiple bettas in a very large community tank. But it's a very big tank - and something I would not attempt to do in anything less than a 55 gallon tank.

well im nervous because he seems to be fine but the other fish seem to be neglecting him what should i do?

-Sarah-

I'm so nervous because now he is keeping his head and the tip of his mouth at the top of the tank water standing there for awhile and then panik swimming in circles, then is starts all over again. I am so worried what should I do?

-Sarah-

I don't think I acted quick enough. He is dead. He looks like he froze to death. but he water is perfect. Thanks for all your guys help

-Sarah-

Sometimes no matter what we do, bettas don't always survive. Quite honestly, I think it's the way their packaged and sold. At some stores, they don't ever seem to change the water in the tiny containers that they're shipped in, and if they aren't eating, the pellets are rotting at the bottom of the container.

So many times, you can wind up picking up betta (or fish in general) who look great when you get them, but they're really harboring bacterial infections or other infections that they wind up succumbing to.

The only thing you can do is try and buy from good sellers who treat their fish well and know what they're doing.