If you live in arizona or socal it's a guarantee, but in NorCal you need to plan it right. Figure it just like you would solar panels. find the side of your house that gets the most sunlight and plan your tank and solatubes around that. If you can manage at least 6hrs of direct sun on a spot on your roof you should be okay. Find out how the sun will move between summer and winter. 6 hrs is plenty. Blue led for spectrum supplement and evening viewing, plus added par.