They Don't Need a Heater. I use a Strong Halogen Desk Lamp, It keeps the Water nice and Tepid. My other Bettas are heated with the same method and they are all nice and active and no complaints from them.
Sorry lads but i think thats cruel, those jars are tiny, i wouldn't put fry in them.
Do you leave the lamps on all night? otherwise the water would get cold especially in the winter
Hey thats pretty cool but do the Bettas REALLY not mind an environment as small as that? I mean do they not even need any gravel? I Would'nt mind getting a couple of 2 gallon tanks for bettas....
Sweet setup ps! I have lots of giant jars like that,but they're all at least a gallon size. A little tip,go look in the craft section every now and then at walmart,they are doing inventory until the middle of june and they are clearing out alot of those glass marbles. I got a whole bag full of different kinds for 50 cents a bag,normally $1.50 a bag,they look great and they are super easy to clean. That's what I use. I hate gravel in those smaller jars,the bettas always snag their tails. Plus I like the cool look of glass rocks/marbles.