Hopwin wrote:
Are we talking about the same kind of fish? They are supposedly one of the hardiest fish out there.
Sort of. Bettas can
tolerate a wider range of conditions than most tropicals, but tolerating or merely surviving is not the same thing as thriving. And they're really only "hardy" if you're meeting their basic needs as tropical fish.
If your betta spends most of his time just sitting there (especially towards the bottom of the tank) with his fins draped close to his body ("clamped fins"
1 2 3), this indicates that he is not feeling well at all. He might
survive this way, but it's no fun for him or you. Unfortunately, most people think this is "normal" for bettas, and are disappointed with them as pets. I could be wrong, but I get the feeling that you're in this category.
Though slow-moving (as compared to, say, guppies), a healthy, happy betta is actually fairly active. They should spend a good portion of their day swimming around, showing off their plumage, and curiously watching things around them. A healthy betta is also prettier, having brighter coloration and holding its fins out and away from its body for better display (
1 2 3 4) They'll also work obsessively on their
bubble nests even if there are no females present. I'll wager that 99% of betta owners have never seen their betta do this.
Occasional fin-clamping is nothing to worry about if your betta is otherwise active -- it may have just tired itself out. And sometimes they
do like to go curl up in a cave, if you have one (particularly if their tank gets any direct sunlight). But they should spend most of their time out and about where you can see and enjoy them. Active bettas also live longer and are less prone to disease, which means less work for you.
That said, if you you
really want to keep the betta in the same tank as the goldfish, this isn't entirely impossible. At a bare minimum, get a small tank heater and a thermometer. Raise the temp of the tank (gradually) to about 76-77F. This will make your betta much happier, and it's still within the range that goldfish will find pleasant. Because it's co-habiting with other, messier fish, treating the tank water with a little bit of Aquarisol (or similar) would be a very good idea. It's cheap and lasts a long time. Of course, you also need to dechlorinate it, but that's not unique to bettas. Chlorine is bad for pretty much all fish. You might even find some kind of all-in-one betta water conditioner at your local pet store that dechlorinates, mineralizes, and adds anti-fungul/bacterial agents. Another good thing to add (believe it or not) is rock salt or aquarium salt -- somewhere between 1/4 teaspoon to a tablespoon per gallon. Salt is a "gentler" way of making the water less appealing to bacteria and fungus than chlorine (which you should be neutralizing).
As for aeration and filtration, you don't really have any choice except to use what's necessary for goldfish. Bettas don't like that much water motion, but it isn't bad for them, per se. You'll just have to live with the fact that your betta will probably never build bubble nests because of the surface disruption. He may also develop shorter, less impressive fins because of the extra water current. They only grow out their full length plumage as an aid for swimming in still, shallow water.