I have a 10 gallon tank, The heater broke, and I was wondering if I could use a 100 watt heater for a 10 gallon, and have it still be okay or would it be to much , should I go and get another 50 watt?
The 100 watt should be ok, you'll probably have to set it several degrees lower than you want, since it's more powerful. Just keep a close eye on it, because it will cook your tank faster than a 50 watt if it shorts out.