Sand filter for new pool?

ferretbone

In The Industry
May 24, 2016
164
tx
You appeared to be suggesting that all filter types can filter particles smaller than the limits of human visibility, and that therefore there will be no visible difference in water quality between filter types.

I’ve heard that argument several times, but it doesn’t make sense to me, as a large number of smaller particles could get thru the filter, and be visible in larger numbers, regardless of whether individual particles are too small to see.
What's not to understand? Sand filters do filter down to 25 microns, and you can't see anything under about 40 microns. Sand filters clean water so clear that you can't see particles in the water x about 2.
I see what your problem is. You stop thinking after "filters down to the limits of human visibility". But then you forget the process repeats, then repeats again, and again etc. Which means there will never be enough particles to collect into bigger, and bigger particles that you can see.

I can see atoms with the naked eye you know, and by atoms I mean water, waves, bubbles, fumes, fire, smoke, blood cells, and even bacteria.
Let me ask this, can you see algae coming out of your jets right now? Oh wait you might have a DE filter. Then can you see the algae floating in the air or across the pool surface? Because it's there even in the pools with DE filters. Can you see it floating in new or old pool water before or after chlorination? Can you see floating bacteria in spring water?

Have you ever seen a bunch of human skin cells floating around in pool water? How about white blood cells, or red blood cells?
Can you see singal particals of pollen floating in your water? You can't (about 30 microns), but you have seen pollen on your car, or on tree leafs etc. You have also seen blood, skin, algae, pollen, dust, smoke, carbon dust, and yes even bacteria somewhere right? I have.

Can you see any of that under water in a clean clear blue pool looking at the other side? Yeah sure, maybe, maybe not. Depends how much of each and what particle is in there with you, and how far across your field of view is.
You can't see singular smoke particles in the air, but you have seen smoke. Yeah sure most of us have not seen smoke in a pool or (fog), but if enough of those smoke particles are in the air together, I'd believe you if you told me you can see smoke. Because I can too.

So can you see anything at 25 microns by the pool light? No you can't.

But can you see anything under 25 microns grouped together in large mass like blood cells, algae, pollen, or even smoke across a long enough field of view, with enough mass holding it. Or maybe in front of a pool light? Yeah I guess we all can. But not if they are filtered, again, and again, like pool filters do, so that they do not become big enough clumbs of Crud that you can see. Instead that stuff gets filtered, and the only things passing through the fitler is the small singal particals of Crud you can't see going back to the pool.

I stand by my statements, sand filters, filter enough small particles out of the pool water that you can not see the difference between the quality of other filters. And you knew that was what I meant, and have added nothing to this thread.

If it's big it get filtered.
If it's small it passes through to the pool.
Until small collects enough together to become big.
When it does the big gets filtered.

At no time is the sand filter putting out anything that can't be filtered down to the limits of human visibility. Got it?

edit: After all that small stuff collects in the pool body after being repeated through the filter, what do we use to finish the process and oxidize everything left over in the water?
 
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tomfrh

Well-known member
Jan 30, 2018
541
Australia
At no time is the sand filter putting out anything that can't be filtered down to the limits of human visibility. Got it?

and filters do filter down to 25 microns, and you can't see anything under about 40 microns. Sand filters clean water so clear that you can't see particles in the water x about 2.
I see what your problem is. You stop thinking after "filters down to the limits of human visibility".

Small particles needn’t accumulate into larger particles to be seen. Fog particles are 1-5 microns, but you can see fog just fine.

If a sand filter is letting through particles in the 5-25 micron range that would result in reduced water clarity, would it not?
 
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ferretbone

In The Industry
May 24, 2016
164
tx
Small particles needn’t accumulate into larger particles to be seen. Fog particles are 1-5 microns, but you can see fog just fine.

If a sand filter is letting through particles in the 5-25 micron range that would result in reduced water clarity, would it not?
No fog can be up to 500 microns. I can see fog. And know one has ever seen fog in a pool. Or smoke for that matter, stop using those because it makes no sense. Fog and smoke do not collect, or appear in swimming pools.

What is collecting in the 5-25 micron range in a pool that is not being oxidized by chlorine?
 

tomfrh

Well-known member
Jan 30, 2018
541
Australia
No fog can be up to 500 microns. I can see fog. And know one has ever seen fog in a pool. Or smoke for that matter, stop using those because it makes no sense

Fog is suspended particles in the range of 1-5 microns. These suspended particles can heavily affect clarity and visibility, despite the individual particles being too small to see. Likewise smoke, which are even smaller particles. Similarly, suspended particles in the sub 25 micron size range can affect pool water clarity/visibility, despite the individual particles being too small to see. If a DE filter is filtering more of these tiny particles then it stands to reason that the DE can produce clearer water than a filter which isn't. This is certainly what people claim to see in DE pools.

What is collecting in the 5-25 micron range in a pool that is not being oxidized by chlorine?

Silt, clay, dust, etc...
 
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ferretbone

In The Industry
May 24, 2016
164
tx
Fog is suspended particles in the range of 1-5 microns. These suspended particles can heavily affect clarity and visibility, despite the individual particles being too small to see. Likewise smoke, which are even smaller particles. Similarly, suspended particles in the sub 25 micron size range can affect pool water clarity/visibility, despite the individual particles being too small to see. If a DE filter is filtering more of these tiny particles then it stands to reason that the DE can produce clearer water than a filter which isn't. This is certainly what people claim to see in DE pools.



Silt, clay, dust, etc...

Yeah like I said I've heard about the outbreak of fog in swimming pools. If you can see it floating across your flash light beam it is not 1-5 microns. It's far larger. Do you know how we can all tell? Because we can SEE it. It's larger than 5 micron. Anyway even newbie pool owners like the OP don't really have a big fog or smoke problem with their new swimming pool water so we should move on.

In your world silt, clay, and dust, just blows across your neighbors yard into your pool? And you can see it. Welcome to my world, reguardless of what filter you have you will need to clean these money pit swimming pools from time to time, and filter them, chlroinate them etc.

Besides most silt, clay, and dust get captured by sand filters as well.
You are right though a DE filter will catch more soot etc the first go around. But you can not see the difference between a DE, or sand filter pools water clairity all things being the same.
 

Rocket J Squirrel

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This discussion has derailed way off the tracks. Microns, shmicrons. The question is whether you want to deal with a messy filter medium like sand or DE, or use a no-muss, no-fuss cartridge filter.
 

ferretbone

In The Industry
May 24, 2016
164
tx
This discussion has derailed way off the tracks. Microns, shmicrons. The question is whether you want to deal with a messy filter medium like sand or DE, or use a no-muss, no-fuss cartridge filter.
Not necessarily, I'm making a case for sand filters beginning just fine for any app. I recommended a sand filter for a new pool guy, and he will be set for life off my recommendations. No mess no fuss for years with half the effort.
 

Rocket J Squirrel

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I'm making a case for sand filters beginning just fine for any app. I recommended a sand filter for a new pool guy, and he will be set for life off my recommendations. No mess no fuss for years with half the effort.
Until he uses flocc and turns the sand into a mess. Then he'll have twice the effort.

A big Nope on sand for "any app". In drought regions and locales where backwashing is forbidden, cartridge is the only choice.
 
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YippeeSkippy

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Until he uses flocc and turns the sand into a mess. Then he'll have twice the effort.

A big Nope on sand for "any app". In drought regions and locales where backwashing is forbidden, cartridge is the only choice.
Absolutely.... there are areas where DE is not allowed, but are also under water restriction. There are areas and members here who for whatever reason can not use extra water to wash filters. Thankfully, with three filter options (sand, cartridge, DE) everyone can find a filter that suits their needs.

As a sidenote- I do not personally ever suggest anyone bother with "sand alternatives" as sand works excellently. Remember that one can also add a little DE to the sand filter (via explicit directions in PoolSchool) to capture smaller bits and really "polish up" the water.

Maddie :flower:
 
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Newdude

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I mentioned fog and smoke as they are examples of how tiny particles can affect clarity despite the individual particles being too small to be seen.
Yes. Because there is a bazillion particles of it with nothing cleaning it. Blow it through a dryer sheet and most of it disappears. The filter is doing it’s thing everyday so you only amass so many at any given moment, and you can’t see them yet by the time the pump kicks back on and starts removing more.
 

Newdude

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So do you agree DE filters don’t produce clearer water
Correct. Not that we can tell anyway. I believe people think they see different results in a placebo way. Also, many times when someone is unhappy with a too small filter, the new style that they go to is much larger and performs better. So the old style filter takes the blame when it’s really not it’s fault. It would have done the same job if it was upgraded in size too. Wanna see the proof ? Head on over to the TFP clear thread. You tell me which ones have which filters.

 
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Bperry

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What about looking underwater with a mask, from one end of the pool to the other? Will you get more clarity from DE?
Swimming in my fathers pool which uses DE and mine which uses sand, I can’t tell any difference with a mask or not. Just some reference information.
 

Newdude

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Not for nothing, Apple tries it’s darndest to convince the sheeple that they need that new 8k resolution phone……. Like they could tell the difference on a 5 inch screen…….. but they are lined up around the corner to spend $1500. :ROFLMAO:
 
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TKpool7683

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Swimming in my fathers pool which uses DE and mine which uses sand, I can’t tell any difference with a mask or not. Just some reference information.
I believe this. I previously had a sand filter that worked amazing and am using sand in my new build. I don't have a study to back it up, but I've always had the understanding the human brain can only process something like 0.5% of all stimuli, so even if we could tell the difference, what's the likelihood that is what gets processed.
 

Bperry

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I believe this. I previously had a sand filter that worked amazing and am using sand in my new build. I don't have a study to back it up, but I've always had the understanding the human brain can only process something like 0.5% of all stimuli, so even if we could tell the difference, what's the likelihood that is what gets processed.
I’d say if the pool get lots of rain that fills up the pool constantly, a sand filter seems to be just fine since you can backwash our the extra water for a free cleaning. If water shortage or cost was an issue, I’d go for the cartridge filter. After seeing the mess that happens with my fathers DE filter when it has to get cleaned, I wouldn’t want to mess with all that.
 
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tomfrh

Well-known member
Jan 30, 2018
541
Australia
Correct. Not that we can tell anyway. I believe people think they see different results in a placebo way

Yeah that’s certainly a possibility. I know that phenomenon happens all the time in all sorts of circumstance.

But by the same token it’s hardly a woowoo proposition to suggest that finer filtration will result in additional water clarity.

All those pools look nice. And I don’t doubt you can get nice looking water from sand and cartridge. I have from mine (I’ve never owned a DE pool). I’m just not sold however that finer filtration of DE is purely placebo.

Swimming in my fathers pool which uses DE and mine which uses sand, I can’t tell any difference with a mask or not. Just some reference information.

Thanks. Good to hear direct evidence. That’s what counts.

What’s the mess of DE? Can’t you backwash down the sewer? Or is it not so easy?
 

Bperry

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Yeah that’s certainly a possibility. I know that phenomenon happens all the time in all sorts of circumstance.

But by the same token it’s hardly a woowoo proposition to suggest that finer filtration will result in additional water clarity.

All those pools look nice. And I don’t doubt you can get nice looking water from sand and cartridge. I have from mine (I’ve never owned a DE pool). I’m just not sold however that finer filtration of DE is purely placebo.



Thanks. Good to hear direct evidence. That’s what counts.

What’s the mess of DE? Can’t you backwash down the sewer? Or is it not so easy?

Yeah that’s certainly a possibility. I know that phenomenon happens all the time in all sorts of circumstance.

But by the same token it’s hardly a woowoo proposition to suggest that finer filtration will result in additional water clarity.

All those pools look nice. And I don’t doubt you can get nice looking water from sand and cartridge. I have from mine (I’ve never owned a DE pool). I’m just not sold however that finer filtration of DE is purely placebo.



Thanks. Good to hear direct evidence. That’s what counts.

What’s the mess of DE? Can’t you backwash down the sewer? Or is it not so easy?
He has a pool service so I haven't actually watched the process, but the next day the cement deck is covered with DE. DE can be considered hazardous to animals so I'm not sure what the disposal legalities are, especially where they are in CA.
 

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