I was wondering... since that 7 watt heater I bought always overheats the 5.5 gallon tank, do you think that it would perhaps warm the 10 gallon tank the right temp? I know it says not to use it in a tank over 5 gallons, but why exactly is that? Does it have to do with the fact that it won't heat the whole tank correctly? Doesn't it then make some sort of sense to think that since it doesn't regulate that using it in a larger tank would help keep the water cooler? If this doesn't make sense to anyone else please let me know. I was just wondering if it would work.