hi welcome to fl. is your issue that you keep having to start your tanks over because you keep having problems?
how are the bettas doing in your tank? it's usually recommended that each
betta be kept alone.
also, is your tank cycled? in my opinion, most tank issues arise from an uncycled tank (although clearly not the callamus worms). If you aren't familiar with the
nitrogen cycle, please click on the link and read up on it. Your tank info says you understand it. Do you know what your
ammonia,
nitrite, and
nitrate readings are?
hmm... also, if your tank is 40 gallons, you may be overstocked...