starting a new tank

[Tacoyaki]

ill check it out tomorrow thanks for the great advice =], btw im contemplating with getting a heater. Since it's summer and it gets pretty hot will i need a heater? I haven't installed one in the tank but i've been closely watching the water temp. During the day it goes into the 28-30c and at night it falls down to 24-26. Would this be good enough? or should I go for a heater?