If it is like a black clump then its your fishes feaces(crap).clean it out
6inch
No, they are fighting fish. They will kill each other no matter what sex they are.
Any decent quality aquarium store should be able to bring in female betta's for you.
most of the time but with betta fish no they can live at room tepature
No. Charcoal bits will harm your betta fish. But you can use deactivated charcoal bits
It is the silicon glue substance that holds together the walls and floor of an aquarium
You should only have 1 fish per gallon of water in a fish tank. I wouldn't put more than 2 or 3 Neon Tetras in a 4 gallon aquarium with 1 Betta.
Male betta fish can be housed in both bowls and aquarium. In order to thrive though they need the proper lighting and filtration.
every two weeks then change the water every four
The black plastic around the edges of the aquarium are simply referred to as 'trim'.
You can get a glass LED aquarium kit food plants and rocks.
you can not simply keep two betta's safe in one aqaurium. for them two be safe you need to use separate aqariums that are distant from each other or use a betta aquarium divider that is not clear so they can't see each other.