Filtration question

Newdude

Well-known member
Jun 16, 2019
2,566
NY
Also question for @Jimrahbe and @JamesW . How well does the water mix when only filtering half of it. So the whole pool turns over through 2 pumps and only half of it goes through the filter. On the next turnover, another half of the water got filtered so 50% gets closer to 75% not factoring in mixing (which there has to be some extra math involved there). So then on the 4th turnover somwhere around 12.5% never went through the filter, and many percent only went through the filter one time in 4 attempts. My pool has to have pockets of water that miss the filter on several attempts, but with the overwhelming majority making it, it is close enough. Would his be more similar to only getting 1 or 2 turnovers a week and if so would that mess things up ?
 
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Newdude

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Jun 16, 2019
2,566
NY
Depending on if the overall water mixes in his favor or not there could be 1/3rd of it that misses the filter each week, maby longer, no ?
 

Newdude

Well-known member
Jun 16, 2019
2,566
NY
Guys this was about the guy who wanted to hook up a 2nd unfiltered pump. It was a question about how it may affect his filtration and got put here as a new question.
 

Jimrahbe

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Jul 7, 2014
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ND,

The idea that you have to have X water turnovers per day is just a myth... Chemicals keep your water clear and sanitized, the filter is just there to capture what falls into the pool. Most of that goes through the skimmer. What does not go through the skimmer gets picked up by your robot, or if you are still trapped in the 60's, your pool cleaner.. :)

I can't see where having two pumps would have any impact as to how well the pool was filtered..

Thanks,

Jim R.
 

Lskul60

Well-known member
May 29, 2019
107
Long Island
Also question for @Jimrahbe and @JamesW . How well does the water mix when only filtering half of it. So the whole pool turns over through 2 pumps and only half of it goes through the filter. On the next turnover, another half of the water got filtered so 50% gets closer to 75% not factoring in mixing (which there has to be some extra math involved there). So then on the 4th turnover somwhere around 12.5% never went through the filter, and many percent only went through the filter one time in 4 attempts. My pool has to have pockets of water that miss the filter on several attempts, but with the overwhelming majority making it, it is close enough. Would his be more similar to only getting 1 or 2 turnovers a week and if so would that mess things up ?
The actual math here is what’s called Zeno’s paradox. The case being that if you are a certain distance from an object (let’s say a wall), and each step you take is half way to the wall, you will never actually reach the wall.
 
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Newdude

Well-known member
Jun 16, 2019
2,566
NY
Yes exactly. And there is even more math because the water mixes so some may take more steps and some may take no steps.
 

duraleigh

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Apr 1, 2007
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Sebring, Florida
I can't see where having two pumps would have any impact as to how well the pool was filtered..
+1.

Y'all are doing math like the water was a solid. A fluid mixes and intermingles constantly seeking equilibrium. There is a $13 dollar college word for that characteristic but I forgot it.
 
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Newdude

Well-known member
Jun 16, 2019
2,566
NY
ND,

The idea that you have to have X water turnovers per day is just a myth...

Thanks jim. I get the old myth about the daily turnover. I was wondering if it would be a weekly or longer turnover due to the 2nd unfiltered pump. I figured that might amount to alot of sediment left in the pool, but like you said most of it ends up in the skimmers so i'm probaby just over thinking.

Thanks
 

Lskul60

Well-known member
May 29, 2019
107
Long Island
+1.

Y'all are doing math like the water was a solid. A fluid mixes and intermingles constantly seeking equilibrium. There is a $13 dollar college word for that characteristic but I forgot it.
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