So I have empty tanks with no where to be set up in the house and if anyone is like me they know that its hard no to want to set them up somewhere and get fish in them. I was given the ok to set up however many tanks in the garage that I would like and so with me wanting to get back into breeding and expanding my bettas I thought perfect i have as much room as I could possible need. One problem out here in CA for some reason is colder than normal and gets into the 30s at night so I figure I better make sure I can heat a tank and make sure it is suitable for the tanks to stay out there. So i set up a 20gh that i have with a 150 watt heater and filled with as cold of water that I could to see if the heater could heat it up to the right temp and good thing is the temp stayed stable all through the night and day but it would only get up to 69 which is no bueno. So I would like to know is can you all think of a more efficent way to heat them without having to buy a million heaters? Do you think instead of heating one big divided tank would it be easier to heat multiple 5 gallon tanks? Any ideas that you have will help alot thanks.