i'm running my pump at night. bad idea ?

[Phillbo]

I only run mine at night due to cheaper electricity during off peak hours.. I'm curious to see the debate on this one as well.

[chem geek]

At higher CYA levels, keeping the water still may help reduce chlorine consumption because the chlorine will mostly be degraded near the surface but the CYA will help to shield the chlorine from breakdown at lower depths. We don't know this for a fact, but this might be the case. If you try this, let us know if it works and by how much.

As for when and how long to run the pump and for preventing algae, there are two reasons to run the pump:

1) To filter the water. It doesn't really matter when the pump is run or whether it is done all at one time or spaced throughout the day. The main principle is how many turnovers of water (i.e. how much total water volume) is filtered per day. The rate needs to be high enough to filter the water faster than particulate matter builds up in it and this process is slow. Typically, one turnover per day is recommended, but this really depends on how much junk gets into your water. If the water looks dull or cloudy and its not an algae bloom (chlorine consumption hasn't gone up significantly) and calcium carbonate water balance is OK, then more filtration time is needed.

2) To circulate the water. This can also be accomplished through stirring such as from a pool cleaner, but the pump plus strategic placement of the returns, skimmer and floor drain allow for even distribution of chemicals and for a circulation pattern that tends to cause floating debris to end up in the skimmer. It is this circulation function that helps prevent algae because a localized lowering of chlorine level in an area of the pool can allow algae to grow.

So it is point #2 that your pool guy is worried about. By not having the pump on during the day, the lack of circulation could promote algae to grow during the time of day when their growth is most rapid (due to sunlight). I think the risk is low, especially if you maintain proper chlorine levels and do at least one turnover at night.

Richard

[brent.roberts]

Chem Geek has the principals correct.

I split my run time just so the water gets stirred up a couple times a day.

[CarlD]

Rent a gang of 10-12 year old boys to stir your pool everyday. They'll be happy to for pizza and soda!

[Phillbo]

Can I use 20 yo college girls instead ?

[Spensar]

Can I use 20 yo college girls instead ?

Good luck with just soda and pizza!

[AnnaK]

I run my pump from midnight to 0600 when the rates are low. And I switch it on when the dogs are in the pool and for a couple hours after to skim the dog hair.

I've been doing this for 2 weeks ever since we got the timer and have not noticed a difference in chlorine levels, Cl consumption, or any new and unusual algea blooms. I test the water daily with a Taylor kit.

My new plan is to run the pump on recirculate during swimming and on filter during the night.

And my really new plan is to sit on the pool deck with my .22 and shoot Japanese beetles. Before they land in the pool. They are b-a-a-a-a-d this year!