While working on the pool a month ago, I noticed (besides the collection of leaves and dirt from the Santa Anas) that my pool holds 52 F all of the time. It is a 30,000 gallon pool that gets no direct sun and won't break 70 F until mid-July So my first lager, a Maibock, is fermenting happily in a carboy on a step. It is wrapped in foil and T-shirts so light is not an issue. We also have no critters that can reach 2'+ and reach the airlock. Are there any flaws in this I might have missed?