Frogs are amphibians ... xD
Anyways, the nerite won't adjust the heater. lol just buy both the nerite and the betta. Also, when adding the new betta to the tank (whether you QT him or not), have him in a container and let him float for an hour or so. It won't hurt him. I do this to let my fish see their new environment. I notice that if I do this with new bettas (females in the community or males in divided tanks (or even new, big tanks)) then they don't get as stressed. The thing is that they get to stay in the safety of the cup, but see their new surroundings and get used to everything.
100g Native Fish Pond, 55g Goldfish/Catfish Community, 50g Plant Pond, 40gB Tetra/Cory Community, 20gHM Community, 20gH Turtle (Bender [RES]), 20gL Turtle (Kif [YBS]), 15g Reef, 5.5g Betta (Okami), 5gFBH Betta (Pron), 5gHex Betta (Twister)
2 dogs, 13 cats, 2 turtles, 1 bearded dragon and 1 crested gecko