1) with a 2.5 gallon tank, the only companion you can really get is a snail. Which are very cute and I love them.
2) Yes, you do still need to condition the water. I recommend using Prime since it also protects your fish from ammonia for a very short period of time.
3) Males usually have the longer fins. Females will have shorter fins and you'll also notice a "egg spot" on the belly of the fish between the pectoral fins
4) bubble nests don't really mean the fish is happy. Making them is a normal thing for them. They make them out of boredom, for no reason, because its close to breeding time for them, and many other reasons. Sick fish will make bubble nests as well. I'm not saying your fish is sick, Its just a common misconception that when bettas make bubble nests they are happy.
2) Yes, you do still need to condition the water. I recommend using Prime since it also protects your fish from ammonia for a very short period of time.
3) Males usually have the longer fins. Females will have shorter fins and you'll also notice a "egg spot" on the belly of the fish between the pectoral fins
4) bubble nests don't really mean the fish is happy. Making them is a normal thing for them. They make them out of boredom, for no reason, because its close to breeding time for them, and many other reasons. Sick fish will make bubble nests as well. I'm not saying your fish is sick, Its just a common misconception that when bettas make bubble nests they are happy.