Whata re you people with cold ambient temps in winter doing for heaters? I've got a 42g cad light with around 20gallons in the sump. I will be adding a lid soon, but curious what kind of power people with similar sized setups are doing for power. I had a 100w heater and it couldnt get it past 68 over a few days. This eheim I have right now is a 150w and it's been in about 5 hours and its up to 70. I'm starting to think I should be considering 300+w of heater. the house was 62 when I got in this evening, but it will get colder when I travel for work, probably 50? I know a lid will help a bit. Looking for opinions. I feel like i'd be better off with a much larger heater