How to Take Care of Japanese Fighting Fish

Keep your Japanese fighting fish in the largest tank reasonable for your budget and space. Although these fish can survive in rice paddy puddles and are sold in small containers, they typically have the best colors and optimal health when housed in tanks that hold at least 10 gallons. Smaller tanks quickly become contaminated with waste that can dramatically reduce your fish's life span. Cover the tank with a ventilated tank lid because bettas are very good jumpers. In addition, keep the tank only about 80 percent full of water to keep your fish from leaping out.

You can safely fill your fighting fish's tank with chlorine-free tap water or bottled water, but never use distilled water in an aquarium. Allow tap water to stand for about 24 hours so it reaches room temperature before you add it to the tank. If you live in an area with very hard water, use water treatment chemicals available at aquarium supply stores to remove possible contaminants. If you opt to use bottled water, keep using the same brand to avoid stressing out your fish. All waters are not the same, so make gradual changes to allow your fish time to get used to differences.

Feed your fish once a day with food specifically made for bettas. Japanese fighting fish have small appetites, so drop in just three to six pellets per feeding. Remove any remaining food after five minutes so it doesn't rot and contaminate the water. These fish enjoy snacking on freeze-dried bloodworm and brine shrimp, but use these as treats and not in place of a meal.

Even though these little guys breathe air, you still need to keep the water clean. If you're using a 1-gallon tank or larger, change about 25 percent of the water once a week. Smaller tanks need 100 percent water change three times a week, minimum. Remember to siphon any excess bits of food and debris out of the gravel when you change the water.

Use an aquarium thermometer to protect your fighting fish from dramatic changes in water temperature. These fish are easily stressed by change and can suffer from various health issues as a result. Bettas thrive in temperatures ranging from 72 to 82 degrees Fahrenheit. Because these fish breathe at the surface of the water, you typically don't need filters in tanks smaller than 5 gallons. For larger tanks, use a small filtration system with an adjustable current and keep it on the lowest setting. A hard current can easily tear your fish's fragile fins.

Never put two male bettas in the same tank -- those highly territorial fish will fight to the death. Avoid placing bettas in tanks with fin nippers, such as sharks or barbs, or fish with big, colorful fins, including goldfish, guppies and angelfish. Male bettas generally live peacefully with platies, plecos and danios. Up to eight females can typically share the same tank if they have ample space for swimming and live plants so they can hide from the dominant females.