well...you need a thermometer to CHECK the water's temperature, but whehter or not your water actually need a heater is another story. Just becuase your house is 79F doesn't necessarily mean the WATER is 79F just get a cheap thermometer and check the temperature, if it's constant and doesn't drop too much during the night the bettas should be alright
It's best to have a heater to be sure the temperature stays constant for breeding, plus for breeding you really want it between 80-84F. The fry won't be able to handle a constantly changing temperature, even if it's only a couple of degrees. Also if your room is 79 then the tank water is probably a couple of degrees cooler, so a bit low for spawning (although some Bettas will breed in any conditions, Lol).
Heh my room is 76 but my tank is 80. The heater in the tank is set to 75 but since its 80 it never comes on. Go figure. Anyways yeah a cheap stick on thermometer is a good idea so you can see what the temperature actually is in your tank.
i meant heater but oh well ill get both, im already over my fish budget for this month, i try to limit myself for fish, and i bought a phython syphon (works great)
I'm getting a heater/10 gallon tank for my Betta Saturday. I already have his thermometer in there, and he loves to poke his nose next to it and stare at it. I'm suspecting that hes having romantic dellusions about the silver coloration on the bottom of it
Anyway, I definitely getting one since poor Mono's water is at 70ish.