Just bought the Juwel Rio 125 as a second tank. As the name suggests, it is a 125 litre tank. It comes with filter, lights etc and a 100 Watt heater. I am concerned that 100 Watts is not even nearly big enough to keep 125 litres at 25 degres celcius reliably. Am I being over cautious here? If not, how do Juwel get away with selling things like this. I choose the Juwel since they seem to have the best reputation, but I am wondering how they manage that.