Incidentally what do I click on to edit my OP

Thanks guys

Oh and

1. What do I click on to edit my OP and

2. Why sometimes do I get a message indicating that I cannot post a followup

Sorry please ignore 2. above. I just learned that one has to change the "subject" entry

Again forgive my massive ignorance

I suspect we who are regulars know your ID.

WRT you question of temp, I have to assume you mean the water's temp. Chlorine losses will vary. That is the dependency though. The higher your loss, the longer your run time. If your water temp is lower than say, 55-F, and your free chlorine losses are low with respect to the CYA level, keeping the run time each day minimized is fine.

How much you need to run each day is usually determined by a number of factors. Consider your FC loss, time to make it up, and the capabilities of your pool's hydraulics. Every pool is different.

Scott