The wind is howling outside like a winter storm, but some day it's going to warm up and I'll want to open my in-ground swimming pool. In order to extend the season (I live in Maryland), I'm thinking about either a solar blanket or a "pill". The former appear to be made out of the same bubble wrap you see in packing, and require a reel to take them off the pool. The latter is apparently a substance that slows down evaporation, which presumably is the main form of head loss.
The pills are not supposed to be as efficient as the blankets (perhaps the blankets have a slight insulating value, and at a guess they're better at retarding evaporation); the ad claims 60% of a blanket's efficiency. On the other hand, a blanket plus reel for my size pool (22x44) costs a minimum of $700 and are warranted for 6-8 years, while the "pills" cost maybe $30 for a four-pack and last "up to" 30 days (I'd need two at a time for my size pool). So figure four to six per season (a month or so at beginning and end of season). And the blanket looks like a lot of hassle to put on and take off, and to store when it gets hot out, and in the winter.
Presumably the chemical from pill doesn't feel oily when you're swimming.
Thoughts? Given the difference, I'm leaning towards the pill, but I'm skeptical about how well they work. And it's hard for me to do a scientific comparison, since I only have one pool :-).
Mike Maxwell