Poor skimming performance with variable speed pump at low speeds

[ba67]

I've been running my variable speed pump at a low speed at night (1800 RPM). I often find leaves floating on the surface of the water or on the bottom of the pool in the mornings. Skimming action appears to be very poor at low speeds since I rarely find any leaves or other debris in the skimmer basket in the mornings. The only thing I typically find in the skimmer basket in the mornings are alive mice. (The mice are usually sitting on top of the weir door and its hard to get them out of the pool.)

If skimming action is poor at low speeds, should I keep the pump off at night instead? If the pump is off overnight, will the weir door keep mice from getting into the skimmer overnight? If I keep the pump off at night, should I schedule the pump to come back on at 8 am at full speed so any surface debris will make it into the skimmer? Right now, I've got the pump scheduled so it runs at medium speed (2400 RPM) from 8 am - 8 pm and it runs at low speed (1800 RPM) at night from 8 pm - 8 am. The skimmer does an okay job at skimming at medium speed (2400 RPM) but it does a much better job when it runs at a higher speed. I want to save money on electricity so I don't want to run it at a high speed all day but I'd be willing to run it at a high speed for an hour or two if it would help get any overnight surface debris into the skimmer.

 

[HermanTX]

First, I would check if your pool returns are creating a push to the skimmers. Running your pump at a higher speed is fine for a couple of hours. If you have better electricity rates at night or early morning then do that for couple of hours and either go off or move to a slower speed. Also pour in the LC when in high or medium speed to have a better mix of it.

 

[ba67]

First, I would check if your pool returns are creating a push to the skimmers. Running your pump at a higher speed is fine for a couple of hours. If you have better electricity rates at night or early morning then do that for couple of hours and either go off or move to a slower speed. Also pour in the LC when in high or medium speed to have a better mix of it.

I only have one skimmer and 2 returns. The returns don't create much of a push to the skimmer at low speeds. I get wonderful skimming action at high speeds and fair action at medium speeds. To maximize electricity savings without decreasing skimmer performance, would it make sense to keep the pump off at night, run it at high speed starting at 8 am to get overnight surface debris into the skimmer, and then run it at medium speed from 9 am - 9 pm? Electricity rates here don't vary based upon the time of day. It just seems like a waste of money to run the pump at night if the skimmer isn't going to catch the leaves that fall overnight. I'm also wondering if I would find less alive mice in my skimmer if the pump was off overnight since the weir door would be closed.

 

[Darin]

sounds like your low speed is too slow since you say you get adequate at medium speeds.
you should run at the slowest speed you can to get adequate skimming otherwise it is pointless to run the pump.
If you are set on turning the pump off then run it at nite during the cheap electricity hours and shut it off during the expensive hours.
I run my pump as slow as i can to have skimmers work 24/7.

 

[HermanTX]

I only have one skimmer and 2 returns. The returns don't create much of a push to the skimmer at low speeds. I get wonderful skimming action at high speeds and fair action at medium speeds. To maximize electricity savings without decreasing skimmer performance, would it make sense to keep the pump off at night, run it at high speed starting at 8 am to get overnight surface debris into the skimmer, and then run it at medium speed from 9 am - 9 pm? Electricity rates here don't vary based upon the time of day. It just seems like a waste of money to run the pump at night if the skimmer isn't going to catch the leaves that fall overnight. I'm also wondering if I would find less alive mice in my skimmer if the pump was off overnight since the weir door would be closed.

Yes that sounds like a good plan. Since electrical costs do not vary by time of day, run the pump at the medium and high speeds to get effective skimming then have the pump turn off.
Try to add your daily LC requirements at least 30 minutes before the pump shuts off.

 

[Darin]

The only reason to run at high speed is for vac and backwash. If medium works for skimming leave it there.

 

[Jimrahbe]

67,

I have three pools that all have 3 HP IntelliFlo pumps.. Most of the time, the pumps run at about 1200 RPM (Simple pools with no heaters)..

I used to program the automation system to increase the speed several times a day to help with skimming.. I no longer use those extra skimming speeds, as they did not make any noticeable difference.

Skimming with VS pumps looks different, then when using single speed pumps, but I don't see a lot of difference in what the skimmer pics up. I use hairnets in the skimmers and I am always amazed at the amount of 'junk' that ends up in the skimmer baskets.

The key to skimming with a VS pump is patience. Nothing is going to reach out into the pool and grab stuff, but things that fall into my pools tend to either immediately sink, or they end up in the skimmer basket within half an hour or so.

I do set my returns to push the water in a circular pattern, like a very slow moving toilet bowl when flushing.

I also try to keep my water level in the middle of my tile line. The higher the water level, the less skimming action there is. And, you have to have working weir door, or you won't actually be "skimming".

Thanks,

Jim R.