What is the best run time for my pump?

[S Keith]

Split from Mismatched Pump/Filter/Pool combo? Zea3

First post. New pool owner. Thank you all for a great resource!

I glean from these interactions it is important for the filter and pump to have comparable flow rates.

I have a second-hand Aqua Leader 18' AGP ($30) with spherical (100#) sand filter with a 25 gpm flow rate on the label. My pump is a 1hp Hayward at 60gpm. I have the adjustable return angled as far away from the skimmer as it permits and slightly down. This creates about a 3rpm whirlpool that is actually pleasant to float upon. My wife refers to it as "the lazy river ride".

I know the right answer is, "replace the pump with one better matched to the filter." I'm not going to do that. I'm looking to work with what I have. We have already spent a lot opening the pool, and we did it late in the season... it took me a while to design and 3D Print replacements for the irreparably broken resin pieces. I want the "make the best of what you have answer."

While I haven't measured it, I believe I am flowing MUCH closer to the 60gpm rate than the 25gpm rate, which I presume means that since more water is being forced through the filter, it is less effective. While I would like to calculate based on the pump flow as that would turn over my water in 7651gal/60gpm = 2 hrs, 7 minutes to minimize the run time, I should probably use the 25gpm value and run the pump for a little over 5 hours. Is this correct?

Again, I know the BEST answer. I need the, "for what you have, this is the best answer" answer.

Thanks,

Steve

 

[pabeader]

The reality is "turn over" isn't even considered much around here. The best run time for your system is entirely based on your debris level. You only need to run enough to skim the leaves and stuff off the surface. If after a week of that you find areas on the liner the seem to be lees clean then others, bump it up a bit. In your case though that won't be a problem.

 

[Richard320]

Welcome!

Is the water staying clear? Is any floating debris skimming off the surface? Then you are running the filter long enough.

There's an article in Pool School that explains it in greater depth, but essentially, you just keep reducing the filter time until you are dissatisfied with the way the water looks and then go back up. I get by with three hours a day. There are tons more threads where others have replied with what works for them. Try the search box for some results.

 

[S Keith]

Thank you. I appreciate the very practical answers, it's in the spirit of, "if it ain't broke, don't fix it." Personally, I had a bit of a gripe with the concept of turnover as it's pretty much a certainty that you're not going to filter all of the water through the filter in that time frame. Some of them there molecules are going to go double and triple rides through the sand. I think I see it as the pool water is a fairly homogenous solution with a concentration of contaminants. Running a filter for X time decreases contaminants by Y reducing the total contaminants, C. As long as C is below the threshold of acceptability, no more filtration is needed.

The water is fairly clear, but I have yet to achieve favorable chemistry, so I think it can be better. I need to get the CYA to the recommended levels. I'm having a heck of a time keeping up with the FC.

There is negligible floating debris after a very short period of time. The nice thing about the "whirlpool effect" is that the debris on the bottom of the pool settles in a very small area in the middle for easy clean-up.

Based on your criteria, I'm likely over-running the pool by a good measure. I'll read the article.

Thanks again,

Steve

 

[Texas Splash]

Steve, based on your last post with some concerns about water chemistry, you're certainly welcome to post a full set of test results if you would like for us to give you some feedback. While you're trying to dial-in your pump time, maybe we can help you to ensure the chemistry part is under control as well. With your TF-100 or Taylor K-2006, just post your FC, CC, CYA, pH, TA. CH should not apply unless you have an SWG or heater.

In fact, when you get a chance, please add your pool info to your signature by going to the top of the TFP web page (just under the Pool School button) and select "SETTINGS". On the next page look to the left for a menu bar that says, “MY SETTINGS” and go to "EDIT SIGNATURE" to enter your pool and equipment info there. It will help us later.

Have a great day!

 

[Agent99]

In my case, I have solar heating for my pool and so I run my pump longer AND because I need to pump water to the peak of my second story roof, I need some rpms to do that as well. So I can't run my VS pump at 1000-1500 rpm like some folks do. I need around 2400 rpm for my system so it is still slower than a single speed and while I may never recover the pump cost in electricity, I do like the versatility of the pump. It is pretty cool to be able to mess around with the rpms. In my system, my filter shows 15 psi @ 2400 rpm with solar on. If I get down to 2000 rpm with solar on, I start to see bubbles in my return lines and they get noisier. The pressure also drops to 10ish psi. I'm guessing that I'm not getting the water fully through the solar at that point.

Now in the winter (no freezing here), I can run the pump more like 1500 rpm since the solar will be off. That shows about 5 psi on my filter.

I do have a flow gauge in my system and one of these days, I'm going to plot out psi/flow rate/rpm/watt with/without solar on.

You'll notice I'm using my filter pressure to gauge things. A tech at Pentair suggested it as I was trying to figure out what speed to run my IntelliFlo at.

 

[LFrankow]

I myself run a two pump system, one 3/4 hp primarily for circulating water through my solar panels/heat exchanger, and a 1 hp for filtering/flowing water through my SWG and sand filter.
My 1 hp has to run about 5-6 hours per day, so I set it to run 3 or 4 half hour cycles through the day to skim and clear the top of the pool the rest of the time it runs through the night.
The 3/4 hp runs pretty much when the 1 hp doesn't, solar panel is controled via temp (thermostat in solar panel enclosure ) so it cycles on and off, when not circulating through the solar panel it circulates through the heat exchanger.
I use a DPDT timer to control both pumps, when power is off to 1 hp power is on to the 3/4, when 3/4 hp is off 1 hp and SWG are powered up.

 

[S Keith]

Thank you all. I'll update my sig with pool data and post my numbers when I get the right kit. I was using a walmart HTH kit, but I've ordered a K-2006. I've been using the pool calculator, and aside from CYA = 0 and heavy bleach consumption, things are in recommended limits.

I plan to create a solar heater using coils of black drip line tubing. That will likely be in early spring for an early opening as I'm kinda worn out on this project for this season. At that time, I'll run the pump based on heating need.

 

[S Keith]

Testing to see if my signature shows.

 

[pabeader]

I see it! It's a nice one.

 

[tx_pool]

I've wondered about pump run time as well. I have a 12x23 AGP and I've opted to run the pump 24x7. There are several trees over our pool that drop leaves year-round. Are there any 'chemical' disadvantages to running the pump around the clock? I never hear of anyone else doing that. I guess the caveats are primarily electricity usage and wear/tear?

Thanks!

Mike

 

[pabeader]

The best run time for your system is entirely based on your debris level. You only need to run enough to skim the leaves and stuff off the surface. If after a week of that you find areas on the liner the seem to be less clean than others, bump it up a bit.