Hi!

As far as I know lower temps don't affect the readings, but they do affect algae growth, slowing it and making it easier to keep your pool clear of that problem. Once you are around 60 deg F, algae growth is pretty much inhibited. Usually about an hour to two of circulation is sufficient for an adjusted reading but there are exception. Stabilizer, aka Cyunaric Acid or CYA for short, takes 48 hours to a week to show up in readings after being added.