I have an aquacal tropical t115 and a 22,000 gallon pool. Last night the pool was 73.9 deg when I turned the heat pump on at 10pm. This morning at 7 am the temp has only risen to 75.4 deg, so that's 1.5 deg in 9 hours. The air temp last night got down to 52 deg. Baes on the spreadsheet from acuacal's website, this heat pump should manage 2 hrs/degree when the air temp is below 60. Is this expected performance?