I'm very curious about (and if its the wrong board please move, I couldnt decide) how much effort people here put into keeping the temperature of their tank stable? I personally dont put a lot of effort into it. I rarely check temperature, if at all, I just have the heater set to 23 and trust it to work. Last year it broke during winter and I only noticed when I went to clean the filter, it was probably broken for at least a few weeks, maybe longer. Meaning the tank was at room temp (19c during daytime, 16 at night, so somewhere between those values). In summer I dont bother cooling, I just do the weekly water changes so it gets some cooling from that. When changing water, I dont measure temperature, I do it by hand, if it feels about right then thats good enough. I've never lost a single fish due to this, nor has it ever worried me. When I buy fish, I do acclimatise them, but mostly to the water values. My reasoning is that in nature, temperature isnt constant either. Streams and rivers have various layers with different temperatures, warm spots where the flow is less, etc, rainfall and so on, so fish ought to be able to handle a few degrees of difference provided they themselves arent suddenly plunged into warmer/colder water. I know tanks arent nature, and I'm sure there are fish who are very sensitive to this sort of thing, but yeah, how do you guys approach this? Do you measure the temperature of the water you use for changes, do you cool in summer?