Fish aren't eating

Yes. They're on a hunger strike. If you put them both in one tank, one of them will be lively and well fed.

Seriously, something is off in the environmental conditions:

. give them greater variation to their diets

. make sure their tails are intact -not split due to bites and not shreddeed

. dechlorinate the water before adding

. make sure you change a portion of their water weekly

. keep the temp consistant and around 78-84 deg F

. keep the tank out of direct sunlight and give them 'reasonbable lighting ' that may correspond to daylight and nightime


See the following link for more details about siamese fighting fish living conditions:

http://en.wikipedia.org/wiki/Siamese_fighting_fish

"...primarily carnivorous surface feeders, although some vegetable matter may be eaten. In the wild, they feed on zooplankton including crustaceans and the larvae of mosquitoes and other insects, such as flies, crickets, or grasshoppers. Fish which feed on wide range of foods live longer, have richer colors, and heal fin damage more quickly. Typically, commercial betta pellets are a combination of mashed shrimp meal, wheat flour, fish meal, brine shrimp, bloodworms, and vitamins. These fish will also eat live or frozen bloodworms, mosquito larvae, brine shrimp or daphnia."

also try fish base - another excellent resource for fish

http://www.fishbase.net/

Then enter keyword betta splendens

"minimum aquarium size 60 cm"

oops ... that temp range should be lower than I thought. revised 73 deg f - 78 deg f. It won't harm them if you go higher, but never let temps go lower than 72. keep them shielded for temp swings and from direct sunlight which will make algae build and water temps spike high.

Also, you may keep Siamese fighting fish in as small a space as a brandy snifter but temporarily. That is often how some pet stores sell them, but ideally at home the aquarium size recommended for optimal results is 60 cm or 24 inches .

Thank you for your help, the energetic one has gained his appetite back but the other still lies on the bottom of the tank. I am unsure on what to do with him, to be honest the first thing he did when I got him was sink to the bottom of the tank.

You never commented whether any of the adverse aquarium conditions I mentioned applied to your situation?

Perhaps he was sick when you bought him? Or he was old and near the end of his life?

Maybe he is a she and is pregnant? Are you certain of the sex? Females are much less colorful.