Seperate the bettas.
Did the 2 tanks you mention come from your neighbours and might be established? Or are they new?
If you are doing water tests, what are the test results? These will help guide us to what issues you might be having?
When you say you dont know what to do, is that right back to basics and not knowing how to feed them, do water changes etc?
Link to some stickies for new fish keepers etc.
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