getting started with overnight runtime


Well-known member
Nov 12, 2012
Ontario, Canada
I want to reduce my hydro bills by running my vs pump at night rather than 24/7 on low. My off-peak rate (7pm-7am) is half the cost of my on-peak rate (11am-5pm). One article recommended starting at 8 hours but some posts recommend 2-4 hours and state that a full turnover is not necessary. What should I start with and at what rpm? Right now it's at 1250 but I find that it's not enough for the skimmer to adequate gather surface debris. It hasn't been a big problem since we don't have trees, but I find myself manually skimming off more bugs and pollen than my old two speed that ran at a higher rpm.


Mod Squad
May 3, 2014
Laughlin, NV
With a SWCG, run time is mostly tied to the time needed to generate your chlorine, followed by the time needed to keep the water clean.

When generating chlorine at night, you need to be sure you are generating enough that at sunset, you still have target level FC.

Pump speed is first what is needed to close the flow switch on the SWCG, followed by what is needed to skim the pool surface.

Take care.


TFP Expert
Apr 29, 2016
Quaker Hill, CT
Depending on how much you heat the pool running the pump at night with increase your heat loss in the water which might make the economics of saving money to run the pump end up costing you more in lost heat.

If you are running that pump at 1250 rpm it's only consuming around 150watts of power which is about 1kW/hr of use per day.