I need help!!! Dividing tanks

[Lulu5126]

I have 30 bettas in either 10 gallon tanks divided in half or 20 gallon divided in thirds. Dividing the tanks has been good for me thus far, but I have soooooooooo many, I am killing myself. They all have filters, heaters, lights the works, but with this many tanks it takes me two days to do water changes. I see a 12 gallon tank with dimensions of 35.4x8.3x9.4 does this sound like a viable situation for me to cut down on so many different tanks? Really need help here and thank you in advance for all your expertise.
Lulu

[Laki]

I don't see a problem with dividing the 12g 3 or 4 ways giving them each 4 or 3 gallons respectively. You could probably even divide the 20 gallons again and fit in another betta or two to save on filters and heaters.