Hello, I have a densely planted high tech 8 gallon tank currently stocked with roughly 30 neocaridina shrimp. I have been planning on getting 12 chili rasboras, but am unsure if I need a heater. The temperature of my tank sits in between between 70F-74F or 21C-23C. Some websites say that that temperature will be okay and others say that I need to have a consistent temperature. Any help is greatly appreciated, thank you!