Before you can think about getting your Betta companions you need to make sure he is receiving proper care.
Contrary to the popular belief, all Bettas MUST have heated and filtered water. It is vital for any fish to have a filter to break down the toxic ammonia in the water. Without a filter, even if you are doing daily water changes, the fish will essentially suffer from poisoning.
I do not know if the tank is heated, but Bettas need very warm water (80F) to stay healthy and happy. A Betta in unheated water is suseptable to cold-water diseases such as ich and velvet, and they will be listless and inactive.
I don't know what size tank you are keeping him in, but they need at least a 5 gallon tank. The main reason is that a smaller volume of water cannot easily and safely be heated and filtered. But also, Bettas need room to swim around. I have heard so many personal accounts of how much more active a Betta has become simply because he was moved to a larger tank.
I am not trying to make accusations here, but this is a topic I feel very strongly about. If your Betta is not right now, please for his sake move him to a 5+ gallon, heated, filtered tank. Now, just a few questions about your tank...please answer them to help us to help you...
What size is the tank?
Is it heated? filtered? lighted?
What is the temp? ammonia? nitrites? nitrates?
What is your Betta's name?...we like to address them properly

Welcome to the forum, and sorry for all the questions.
