Abstract: A floating pool cover arranged for flotation about the top surface of a swimming pool to provide for passive heating during periods of depressed temperatures and reflection of heat during periods of elevated temperatures is provided as a housing formed with an opaque darkened bottom floor and a convex transparent top, with ends defining a top wall of the housing wherein spaced first and second buoyant chambers are formed coextensively at opposed end walls of the organization. The invention is further arranged to include interlocking pegs received within accommodating apertures between adjacent panels to provide for a matrix of the housings for flotation and accommodation of variously configured pools. Further, the organization may be optionally provided with a releasing chamber to direct chemical into the underlying pool during periods of elevated temperature conditions.