As you might expect, the nights here in MN are still a bit on the brisk side (50ish). I have been leaving the solar cover on each night which has allowed the temp to stay around 80-83 without running the heater. I left the cover off last night to see how much heat I would lose (keep in mind I am running my pump 24x7). Much to my surprise, I only lost about 5 degrees. I thought for sure it would have lost at least 10-15 degrees.
I plan to leave it off for several says with the pump running. Hopefully the aeration and rain will help get my TA down. I of course have an gal on MA handy if needed.