I have an Intermatic timer also but not sure which model. I would suggest that you get a timer that can turn off and on more than once in a 24 hour period. I run my pump from 8:00 AM to 11:00 AM and then again from 3:00 PM to 6:00 PM. I have a 32,000 gallon pool and it stays clean and the chemicals stay balanced. By running in two seperate times during the day, I have noticed that I use less chemicals during the year as well as less electricity!!

Bruce