Hello, I have a question regarding the water temperature for my betta fish. I do not use a heater and leave it in room temperature, and the thermometer in the water says it is usually around 75-80. However, lately the weather's been getting warmer and I noticed the temperature has been around 80-85. I'm worried that it will be getting much hotter in the next month reaching 90s (more or less). Won't that be too hot for my betta? What can I do to keep the water temperature cooler or at the optimal 75-80 temperature? (My home does not have AC but I do have a desk fan, but that doesn't really make the room that much cooler..). Thank you!