|A Crowntail Betta enjoys his garish|
(and hastily-constructed) home.
Bettas are the last "bowl fish" in the industry - they're the last fish that professional fish-keepers still consider appropriately-kept in unfiltered, unoxygenated water. They are, in this respect, very useful from a commercial perspective as a good "introductory fish", since their needs are the simplest, their constitutions the heartiest, and their looks the most attractive. I've often contemplated a "desk betta" (I used to have a far larger desk), specifically because they do well in small volumes.
Saying a Betta will survive in a bowl is a lot like saying a dog will survive in its kennel. Yes, the fish was shipped to the store from Shanghai in less water than you need between lunch and supper to stay healthy. Yes, it has survived weeks on the shelf in heavily-medicated water with no larger a container than a plastic cup. Yes, it can live for months in a well-maintained bowl.
Throw a betta into the ideal conditions, however, and it can live for up to 4 years. Now, that might not sound like much, but when you consider that a ballpark life-span for a betta in a litre of water is six or seven months (unless the casual aquarist is being meticulous about his water-changes), you're talking about improving that lifespan by a factor of eight.
Betta Splendens is a species name that refers both to a particular species, and to a species complex of a dozen or so other closely-related species from the same geographical area. For the purposes of this profile, I will be writing exclusively about the specific fish.
Chemically, Bettas are undemanding. This should not be surprising considering just how stale and inhospitable the water in those little cups you see can get. Ornamental Strains (the kinds you see in pet shops - such as my crowntail, or even the "basic" Betta) are very tolerant of pH and accept water ranging from 6.0 to 8.0; bear in mind that transitioning pH should be done slowly to avoid shocking the fish. Captive-bred fish are also highly tolerant of a range of water hardnesses, but in my experience, colors are best in relatively soft water. Unsurprisingly, they tolerate a range of temperatures from 71-82 Fahrenheit, but I prefer to keep mine (when alone) at 79.
An adult betta with its full pride on will have a length of 6-7 cm, which is a good couple of inches. They're also fairly active under dim lighting, and appreciate a good amount of plant cover, both in the water column and across the surface. For that reason, I find a ten-gallon tank with a base of a foot by a foot and a half to be the ideal for maintaining them.
Taking food can be a bit of a task. Pellets are the easiest to feed (no more than 3 of the nutrafin max pellets per day), though live food should be supplemented often to get the best colour and condition out of the fish.
While there is a certain amount of myth behind the idea that the males fight to the death, keeping males together in anything other than the largest and most well-planted of aquaria is the poor choice. That being said, keeping a male with a small group (colloquially, a harem) of females is a good way to have the energy of a community tank without the difficulty of finding suitable tank-mates for the beta.
These fish also tend to live in standing water that becomes discoloured by decomposition (in the wild), and appreciate additional organic compounds in the water as a result. Treatments containing the extract of beech, oak, or ketapang almond leaves are available. Hagen manufactures such a treatment called Tropical Extracts, under their Nutrafin brand. It's also possible (though energy consuming), to find dry leaves of the mentioned types and litter them across the bottom of the tank.
Let me give an example tank setup, based on the way I intend to retrofit my current betta tank to better suit the poor guy's needs.
Mongkut, meaning "crown" in Thai, is a fitting name for a fine crowntail Betta. After being rescued from an unfortunate heater-burn accident, Mongkut could not have been expecting to move into such an attractive new home!
pH: Stable at 7.0
Temp: 79 degress Fahrenheit
Volume: 10 Gallon (Hagen Marina "10" Kit Tank)
Filtration: Hagen Aquaclear 20 HOB, lowest setting, with wonderfully-scrungy foam sponge for media
Lighting: Stock hood with Life-Glo fluorescent tube (I believe it's 14W)
Plantation and Decoration: "Valley" design with tank sides planted in with Vesuvius Swords and back lined with Green Cabomba. Bare natural-gravel substrate with a bit of driftwood for a visual contrast. Duckweed as a floating plant to provide some top-cover.
Maintenance: 10% biweekly water changes and occasional removal of duckweed. Plant-Gro dosed regularly with water changes. Use of small amounts of aquarium salt and Tropical Extracts, respectively.
Feedings: Monday, Wednesday, Friday - 2 pellets in the morning and 2 in the afternoon. Tuesday, Thursday, Saturday - Pinhead crickets or Bloodworm (as available). Sunday - Fast.
Tank "Difficulty": The main difficulty here will be keeping biological filtration powerful while keeping the water flow as low as is practical. Ideally this would be done with an air-powered sponge filter, but having no experience in constructing or running these devices, I'm sticking with what I know. Apart from that, this tank is about as simple as they come.