First i'll give you background of my experience. Over the last ~3 years or more i have had a 20 gallon high running, Along the way i have had bumps along the way like some sickness outbreaks twice an a algae problem. I had the tank half stocked at best due to budget at one time and it was going smoothly. About 2 months or less ago i lost my last fish to natural cause and i basically shut it down. Then my cousin who has recently picked up the hobby and has a 10 gallon long going down stairs with some female bettas approached me, as he has a another terribly small tank with a male betta and was curious if would be interested in setting back up and adopting him and giving him a home. So i am setting up again so far i have drained the tank out cleaned some mineral deposits off the whisper 20 gallon filter and other misc things using aquarium safe cleaning product from API. I have filled the tank again got my filter running with a carbon bag. i am actually interested in moving away from carbon bag and possibly that filter systems as well maybe ? got my air pump going checked the lines etc need to find my spare air stones i had and stick those in. I discovered after i got it up and running that my 100 w heater is broken as the light is not coming on any more if i attempt to adjust the thing on it. so i am looking for a replacement for that ideally on the cheaper end of things . Ideally one that's still adjustable that i could find at one of the few local places be it like a chain like pet smart, petco or another local place that's not a chain that has been fairly helpful in the past. i am also curious as to some suggested tank makes for the male betta. Also as far getting the cycle going goes i am open to suggestions before i introduce the male to the tank. Should i try to get a filter squeeze from either him or another female who may be able to help me out, her tank is probably more mature as my cousins is fairly new. Or should i get a hardy fish to introduce to the tank first to start the cycle that would be a compatible tank mate.