Sand, glass, DE

[Patti]

Hi all! Lotsa’ questions for ya today!!!
I’m replacing the media in my filter (bought it used, and used it for the last two years- don’t know how long it had been since the sand was last changed).
Last year I developed serious problems with staining and algae (vinyl liner, above-ground, 15’x 26’ Mirage) so I figured I’d start off with new media this year - just to cover all the bases & try to head it off at the pass!
The filter is a Hayward Club Pro High Rate Sand Filter,
Model SM 1906T.
Flow rate=40GPM.
On the filter label it says: .45-.55mm
No. 20 or No. 1/2
Silica Filter Sand
175lbs.

I’ve been reading some of the discussions and I may go with glass because of purported better cleansing abilities and to use less water for backwashing as I don’t want to continually add my BRUTALLY HARD water- possibly exacerbating the stain problem (not sure if I got it 100% resolved by the end of last season)

So, my questions are as follows:
1) Is it OKAY to substitute glass when the label/manual specify silica sand?
2) Are the weights similar?
3) What about the volume?
(How do I determine the amount I need?)

I’ve heard of some people adding DE in conjunction with the glass.
4) How much DE do you know to add?
5) Does it have to be replenished on a regular basis?
6) If so, how much, how often, and do I have to take the filter apart to add it?

I have off-the-charts hard water- very high in calcium…and trying to determine if it’s copper or iron causing the staining grief- but leaning towards copper.
I’ve recently read about some inline filters (supposedly made specifically for pool filling) that can be attached directly to a garden hose. You can get different micron rating but the lowest combination one will filter out particles as small as 3microns- which covers the copper, iron, and calcium.
7) Since both glass and DE filter particles that size, do you think it could possibly resolve the iron/copper (and calcium) issue (and save me the cost of buying the filters)?
8) Can DE be used on it’s own, as the only media you put in the filter?
9) If so, how much do you know to put in your filter?
10) What’s involved with the media maintenance beside regular backwashing?
(It may be well worth the trade off if it keeps the stains at bay!)
11) I buy large bags of DE at the Co-op- spread it on gardens to kill slugs and ants, and sometimes mix it in with the horse’s feed- good for their gut function and possibly keeps parasites under control)
I believe there are different ‘grades’ of DE- one is ‘Food Grade’.
Is there a specific grade that has to be used in pool filters, or does it matter?
12) If it’s a specific grade, suggestions on where to get it?

I’m attaching a couple of pics of some pool sand I bought awhile back. Just wondering if anyone has used it or has any opinions on how it pertains to my questions?
The side of the bag says 49/20…so I’m ‘guessing’ that means .49mm and a #20, which falls within the requirements for this filter.
I also need 175 lbs, and only have 100lbs at the moment. Can I mix another type of silica in, or could I use 75lbs. of DE??
(I think this stuff was pretty pricey if I recall correctly. I want to say like $75 a bag. Does that sound right? (I thought I saw someone quoting under $10 a bag).

And finally…just curious about this one……how exactly DOES one determine if a pump/filter are too large or too small for the size of their pool? Is there a calculation?
(My pool holds (roughly!) 11,500 gallons/43,000L.)
Feedback about any of the above questions welcomed - including any input regarding the inline filters I mentioned that can be put on a hose!! I’m quite intrigued by this option!
Thanks in advance for any advice offered!
Patti

 

[PoolStored]

Hi all! Lotsa’ questions for ya today!!!
I’m replacing the media in my filter (bought it used, and used it for the last two years- don’t know how long it had been since the sand was last changed).

WELCOME TO TFP!!!!

Why? Sand doesn't go bad except in rare circumstances.

Deep Cleaning a Sand Filter

This post will walk you through the anatomy of a sand filter, and then provide a video at the end for how to deep clean your sand filter. The filter used in the photos and videos is a Hayward S180T top mount sand filter. The images are of a similar filter. Obviously not all filters are...

www.troublefreepool.com

So, my questions are as follows:
1) Is it OKAY to substitute glass when the label/manual specify silica sand?

Use sand. There have been several reports of better filtering with glass media, compared to sand, and also many reports of problems with glass media. Some of the suppliers have had problems getting the particle size correct, especially as it can change (ie break down) in shipping. Why introduce a problem?

2) Are the weights similar?

Unknown. Typically there is a measurement in your manual that shows how many inches below the top the sand needs to be.

3) What about the volume?

Same as #2.

I’ve heard of some people adding DE in conjunction with the glass.
4) How much DE do you know to add?

You don't want to substitute DE for any portion of the sand. Some will ADD DE (a cup +/-) to the skimmer to help with filtering. When you backwash it is gone and you would then re-add. I found it didn't help me at all.

5) Does it have to be replenished on a regular basis?

Yes, you add through skimmer after you backwash.

6) If so, how much, how often, and do I have to take the filter apart to add it?

You don't, you add to skimmer.

I have off-the-charts hard water- very high in calcium…and trying to determine if it’s copper or iron causing the staining grief- but leaning towards copper.
I’ve recently read about some inline filters (supposedly made specifically for pool filling) that can be attached directly to a garden hose. You can get different micron rating but the lowest combination one will filter out particles as small as 3microns- which covers the copper, iron, and calcium.

If it is IRON...try this. Simple/effective:

7) Since both glass and DE filter particles that size, do you think it could possibly resolve the iron/copper (and calcium) issue (and save me the cost of buying the filters)?

Will not solve any of these.

8) Can DE be used on it’s own, as the only media you put in the filter?

NO

9) If so, how much do you know to put in your filter?

Don't do it. DE is to fine and will ALL blow into your pool and you will have a mess!

10) What’s involved with the media maintenance beside regular backwashing?
(It may be well worth the trade off if it keeps the stains at bay!)

Nothing. As long as you follow the TFP advice and don't add exotic additives to your pool, except for the deep clean, sand will last forever.

11) I buy large bags of DE at the Co-op- spread it on gardens to kill slugs and ants, and sometimes mix it in with the horse’s feed- good for their gut function and possibly keeps parasites under control)
I believe there are different ‘grades’ of DE- one is ‘Food Grade’.
Is there a specific grade that has to be used in pool filters, or does it matter?

Doesn't matter.

12) If it’s a specific grade, suggestions on where to get it?

Can't remember where I got mine. Someone will weigh in...

I’m attaching a couple of pics of some pool sand I bought awhile back. Just wondering if anyone has used it or has any opinions on how it pertains to my questions?

Sand is perfect!

The side of the bag says 49/20…so I’m ‘guessing’ that means .49mm and a #20, which falls within the requirements for this filter.
I also need 175 lbs, and only have 100lbs at the moment. Can I mix another type of silica in, or could I use 75lbs. of DE??
(I think this stuff was pretty pricey if I recall correctly. I want to say like $75 a bag. Does that sound right? (I thought I saw someone quoting under $10 a bag).

Do not use DE. Yes, if the sand is right size and type, you can mix brands.

And finally…just curious about this one……how exactly DOES one determine if a pump/filter are too large or too small for the size of their pool? Is there a calculation?
(My pool holds (roughly!) 11,500 gallons/43,000L.)

Someone that knows will weigh in and help.

Again, Welcome!

Feedback about any of the above questions welcomed - including any input regarding the inline filters I mentioned that can be put on a hose!! I’m quite intrigued by this option!
Thanks in advance for any advice offered!
Patti

 

[1poolman1]

Best thing to use is filter sand. Filter sand is processed specially for filter use, don't use another sand. You would have to read the bag to know how much glass media to substitute, but I believe a 40# bag is the same volume as a 50# bag of sand. Glass is lighter in weight. Glass media is expensive. Sand shouldn't be much more than $10.00 US.

When DE is used in a sand filter it is literally only a handful to coat the top of the sand bed. It can help clear water a little quicker, especially if there is algae, and is backwashed out at the next filter cleaning. There are cellulose fiber substites that work well for that. Pool DE and garden DE are different. Put 75# of DE in a sand filter and be prepared for a large mess.

Almost impossible to have too large a filter (within reason). Very easy to have too powerful a pump. Google pool pump sizing.

 

[Patti]

WELCOME TO TFP!!!!

Why? Sand doesn't go bad except in rare circumstances.

Deep Cleaning a Sand Filter

This post will walk you through the anatomy of a sand filter, and then provide a video at the end for how to deep clean your sand filter. The filter used in the photos and videos is a Hayward S180T top mount sand filter. The images are of a similar filter. Obviously not all filters are...

www.troublefreepool.com

Use sand. There have been several reports of better filtering with glass media, compared to sand, and also many reports of problems with glass media. Some of the suppliers have had problems getting the particle size correct, especially as it can change (ie break down) in shipping. Why introduce a problem?

Unknown. Typically there is a measurement in your manual that shows how many inches below the top the sand needs to be.

Same as #2.

You don't want to substitute DE for any portion of the sand. Some will ADD DE (a cup +/-) to the skimmer to help with filtering. When you backwash it is gone and you would then re-add. I found it didn't help me at all.

Yes, you add through skimmer after you backwash.

You don't, you add to skimmer.

If it is IRON...try this. Simple/effective:

Will not solve any of these.

NO

Don't do it. DE is to fine and will ALL blow into your pool and you will have a mess!

Nothing. As long as you follow the TFP advice and don't add exotic additives to your pool, except for the deep clean, sand will last forever.

Doesn't matter.

Can't remember where I got mine. Someone will weigh in...

Sand is perfect!

Do not use DE. Yes, if the sand is right size and type, you can mix brands.

Someone that knows will weigh in and help.

Again, Welcome!

H

WELCOME TO TFP!!!!

Why? Sand doesn't go bad except in rare circumstances.

Deep Cleaning a Sand Filter

This post will walk you through the anatomy of a sand filter, and then provide a video at the end for how to deep clean your sand filter. The filter used in the photos and videos is a Hayward S180T top mount sand filter. The images are of a similar filter. Obviously not all filters are...

www.troublefreepool.com

Use sand. There have been several reports of better filtering with glass media, compared to sand, and also many reports of problems with glass media. Some of the suppliers have had problems getting the particle size correct, especially as it can change (ie break down) in shipping. Why introduce a problem?

Unknown. Typically there is a measurement in your manual that shows how many inches below the top the sand needs to be.

Same as #2.

You don't want to substitute DE for any portion of the sand. Some will ADD DE (a cup +/-) to the skimmer to help with filtering. When you backwash it is gone and you would then re-add. I found it didn't help me at all.

Yes, you add through skimmer after you backwash.

You don't, you add to skimmer.

If it is IRON...try this. Simple/effective:

Will not solve any of these.

NO

Don't do it. DE is to fine and will ALL blow into your pool and you will have a mess!

Nothing. As long as you follow the TFP advice and don't add exotic additives to your pool, except for the deep clean, sand will last forever.

Doesn't matter.

Can't remember where I got mine. Someone will weigh in...

Sand is perfect!

Do not use DE. Yes, if the sand is right size and type, you can mix brands.

Someone that knows will weigh in and help.

Again, Welcome!

Hi! Thank you for all your input!
And thank you for welcoming me…but I’ve been a member since 2012! I watched the video and will definitely make one, but…my water looks nothing like these videos I’m seeing with red water- and no sediment on the bottom! (I’m becoming more & more convinced that it is copper…). I’ve heard of this kind of filter before, but using in conjunction with a sequestrant (and/or flocculent).
Perhaps this filter with a sequestrant would get the copper molecules…I don’t know .
We’ll see how things went over the winter when I open it up.
One good thing is that with the type of winter cover I have, the water is below the skimmer in the fall, and in the spring, it has filled back up with the melt water or rain water, so I don’t have to add more well water. (I freakin’ LOVE this winter cover!!! It’s completely clean in the spring- no leaves, no water to pump off, - it’s great!)
I’ve tried all the things that are ‘suppose’ to work on stains, and they were getting lighter, but weren’t totally gone in the fall.
HOWEVER….What I am the MOST worried about is that it ISN’T copper, because that means I have a MUCH bigger problem.
I live on a flood plain where the river does flood- (not always up to the pool) but I also have a very high water table. I discovered some interesting information while doing HOURS of research about these stains that I was trying to get rid of. In floodplains and areas with high water tables, water can get in between layers, and in ground/flood water there is a type of microscopic organism that thrives in those conditions…and…they emit a dark purple/blackish DYE that actually stains your liner from the bottom up!! Isn’t that CRAZY!?!? It would certainly explain the blackish stains (which was why I was thinking it was iron first. They didn’t match the description of copper stains, but I noticed in my cast iron porcelain sink that it was dripping and it left a bluish stain associated with copper…so that’s what has been leading me to think (hope) it is copper. I had also put a solar device in the pool that was supposed to keep algae away and reduce chlorine use. It made use of a copper rod & metal ring. It was the first full summer I had it in (before I knew anything about copper & stains!! ). So near the end of summer I took that out and started working on the stains. I’m kind of dreading even opening the pool because I don’t want to have to deal with it. And to make matters even worse…It was a brand new - (and custom-cut$$$ liner which REALLY upset me.)
So… if all else fails, and the stains are indeed coming from my little dye-producing friends my only option will be to drain the pool & put a heavy duty plastic liner in (it’s a specific weight & type of plastic- just can’t recall). I thought about leaving the other liner in for another layer of protection (cut the coping bead off and duct tape it to the metal). Then put the plastic in to the same height (so NO water can get in anywhere!!!), then put the new pool liner in.
A HUGE P.I.T.A ….but nothing much I can do about it. I can’t leave the stains- they look horrendous.
So basically… I’m fed up with dealing with it- all I want to do is relax and swim- not do millions more hours of work!!!
(Oh btw… that was one reason why I wanted to get new filter media too- I want to start out this year with everything new so I have a better chance of eliminating possible causes as I narrow things down. Plus, I don’t know how many years the people before me had the sand and I just thought it was a little gross ).
So… we shall see…
Thanks again for your input!
Patti

 

[Patti]

Okay! Thanks for the feedback. Sounds like the DE is off the table.
I appreciate your help!
Patti

 

[Patti]

BTW…I heard people quoting sand prices and while I had bought the bags of the Mystic White II sand awhile ago, I thought they were around $70/bag. Just want to check Canadian stores/sellers, and sure enough the cheapest was $61 right up to $101 on Amazon.ca.
I don’t know the differences between sand… but this is ‘supposed’ to be very high quality. Here’s a description of it from an ad.
Mystic White II is the descriptive name chosen to identify this exceptionally high-quality swimming pool filter sand.Its a special grade of pure white quartz sand that meets and exceeds the most exacting recommendations and specifications of major sand filter manufacturers Features. Larger diameter than play sand and has a mixture of white and off-white granules. Angular shaped grains entrap contaminants, increase the flow rate and clean easily during backwash.

---

More about Mystic White II Swimming Pool Filter Sand

Web results​

Patti

 

[Newdude]

Hey Patti !!! The only way to get rid of copper is to drain.

 

[Patti]

Hey Patti !!! The only way to get rid of copper is to drain.

Yup….so I understand… and even then it’s not really doable because the walls are apt to collapse.

 

[Desiato]

Just thought I'd chip in with a bit of info comparing sand to glass as I'm in a bit of a unique situation.

Long story short, I helped change the sand for a friend last year and she had exactly the same sand filter as me. I followed the guidelines and added pea gravel and sand and 9 months on her pool looks great. Now although I have the same sand filter, mine has glass media which I changed about 5 years ago but I've been struggling to filter out the smaller dirt particles. When vacuuming I could see two streams of cloudy water being shot back into the pool and this was after backwashing. I bought 2 large 1 micron filter bags and attached them to the returns and they caught a lot of the dirt but these bags eventually wore out the the Ebay seller stopped making them so that's when I added some DE to the filter (as well as a skimmer sock) but I'm still seeing cloudy water being returned when vacuuming.

Once a week I vacuum my friends pool without any signs of cloudy water returning (or adding any DE or skimmer socks) so whilst this is just a simple comparison, sand and pea gravel seems to be doing a better job than my 'off the shelf', glass media. There may be better glass media out there but now that I've sprung a leak on one of the connectors of the filter (and will need to empty the filter), I think I'll switch back to sand.

Just me experience of the two medias.

 

[1poolman1]

You may have a bad gasket in your MPV or a broken lateral that is allowing the dirt back in.

 

[Desiato]

You may have a bad gasket in your MPV or a broken lateral that is allowing the dirt back in.

Both very possible causes but it has always been this way even before replacing the glass media about 5 years ago (when an internal sand filter pipe broke so had the chance to thoroughly inspect the laterals). I had a sudden loss of water last year which was caused by a bad gasket which was immediately fixed with a new one but the occasional cloudy water return persists. The fact that my friends pool is clearly gleaming without any extra filtration (socks and DE) does seem to point the finger at the glass media. It's not that expensive to buy 4 bags of sand and some pea gravel so I'm going to make the change just for my own curiosity (and inspect the gasket and laterals again).

 

[1poolman1]

I have found that leaving out the gravel has had no detrimental effect on the operation of a sand filter. If it calls for 300 pounds of sand, that is what I load and have fine results. In a filter that size it has been necessary to add 50 pounds back after 5 or so years to restore good filtration.

A "high rate" sand filter, 20gpm/sq.ft. (modern sand filters as opposed to "rapid sand" 5gpm/sq.ft) is designed so that it is only the top 1 inch of sand that does 99% of the filtration. But, the location of that 1" in the tank is critical. The "freeboard" (area above the sand bed) is also designed in for proper water flow. Fifty pounds in a 3sq. ft. (300pound) filter is normal loss after backwashing for 5 or so years.

 

[Desiato]

You may have a bad gasket in your MPV or a broken lateral that is allowing the dirt back in.

Sorry, have only now just seen this reply. Yep, it could be a bad gasket or a broken lateral but I've checked the gasket and it's fine and I doubt it is one of the laterals. It only happens when I'm vacuuming a particularly thick layer of dirt and only when the pressure is slightly raised in the filter so I'm leaning more to it being caused by poor quality media filtration than a physical break of the internals. I still haven't got round to swapping out the glass for sand but I plan to do that soon so I'll find out soon enough.

 

[1poolman1]

What

Sorry, have only now just seen this reply. Yep, it could be a bad gasket or a broken lateral but I've checked the gasket and it's fine and I doubt it is one of the laterals. It only happens when I'm vacuuming a particularly thick layer of dirt and only when the pressure is slightly raised in the filter so I'm leaning more to it being caused by poor quality media filtration than a physical break of the internals. I still haven't got round to swapping out the glass for sand but I plan to do that soon so I'll find out soon enough.

What size bags of sand (or glass) are you using? In the US they are usually 50lb. bags (about 23k). A previous post mentions 4 plus some gravel. A filter your size would usually use 6 bags of sand or 5 and some gravel. A 25" tank my require a bit more.
If there is not enough sand in the tank it will not filter correctly and you will have the problems you are experiencing right from the beginning of filter use.
When you use sand with gravel, the sand eventually mixes with it at the bottom of the tank , lowering the height of the sand bed, changing the "freeboard" and making the filter less effective.