Used sand filter - avail. options & your recommendations

[jblizzle]

Re: Looking for used sand filter - questions.

We generally size the filter for the pool size and the pump for the required flow rate depending on features. The only way this would not work is if there was a very small pool with high flow rate features, which would require a large filter to accommodate the high flow rates.

Posted from my Droid with Tapatalk ... sorry if my response is short

 

[y_not]

Re: Looking for used sand filter - questions.

That is not my experience. On low, I am even able to run my solar panels (when my filter is clean). On high, it is a beast at moving water and not as loud a my previous 1 hp powerflo single speed.

That's pretty awesome it performs that well and with such efficiency. Good info, good stuff!!! Thanks.

Which brings me to this. The "Hydraulics 101" article by mas985, says that for a 20k gal pool I should have 3.7 sq-ft sand filter. That's HUUGE!!! ...Surely that can't be right?

Generally, yes it is.

Well, maybe it is, but it certainly doesn't match up with what else I said.
As, in the rest of my message surrounding that quote, I stated the following.

My aunt's last house had a 40k-50k gal IGP pool. It was a stinkin' monster for a backyard pool.
<SNIP>

The "Hydraulics 101" article by mas985, says that for a 20k gal pool I should have 3.7 sq-ft sand filter. That's HUUGE!!!
I know this (that it's an over statement) because my aunt's pool (which is 50k gal, 2.5x above) had a Sta-Rite System 3 sand filter and I'm pretty sure it was the larger of the 2. Which meant it held something like 350lbs of sand and was about a 3.7 sq-ft filtration area. Her pool stayed quite clean!

According to Mas' article, her pool would have needed 3 of those units. YIKES!!! That would have taken up an entire small bedroom, which was about the size of the pool house.

I just looked up that filter, it's actually a bit smaller than I had remembered, but close. It's as follows.
3.4 sq-ft/300lb

MAS985 says her size pool, assuming it was 50,000 gallons, which I'm pretty sure it was based on its dimensions and at the least no less than 40k gal. Says you'd need a filter with a capacity of 9.3 sq-ft of filtration area. That seems like utter insanity!!!
You mean to tell me that a residential pool owner with a pool that size, which is not uncommon at all. Would need to manage 3, that's right, 3 sand filters? With nearly 1/2 a ton of sand?
They aren't running a sewage treatment plant. LOL
It just doesn't make any sense.

The London Olympics Aquatic Center which has 2 Olympic pools, plus a diving pool only uses 13 filters with a 1 meter deep sand bed. Assuming they're standard sand filters, and they're all 3.7 sq-ft monsters, that's nowhere near enough according to MAS's chart.

Even using a 7.06 sq-ft Triton-II side mount only nets you 92 sq-ft, not the 150 sq-ft required for 1 single 800k gal (rounded avg.) Olympic pool. Let alone the other one and the yet other diving pool.

I'm not at all saying his chart is wrong, I'm just questioning the sand filter portions practical application in the real world.

 

[y_not]

Re: Looking for used sand filter - questions.

We generally size the filter for the pool size and the pump for the required flow rate depending on features. The only way this would not work is if there was a very small pool with high flow rate features, which would require a large filter to accommodate the high flow rates.

So filter based on pool size, then pump chosen, at max, has to be at or under the max flow rate of the filter chosen. Yes?

 

[jblizzle]

Re: Looking for used sand filter - questions.

Basically.

 

[linen]

Re: Looking for used sand filter - questions.

So filter based on pool size, then pump chosen, at max, has to be at or under the max flow rate of the filter chosen. Yes?

Yes, though max flow rate also depends (a lot) on plumbing. Most often 1/2 to 1 hp pumps work for most pools without high volume water features. The exception would be a large sand filter, then you need to ensure you have enough flow for backwashing.

MAS985 says her size pool, assuming it was 50,000 gallons, which I'm pretty sure it was based on its dimensions and at the least no less than 40k gal. Says you'd need a filter with a capacity of 9.3 sq-ft of filtration area. That seems like utter insanity!!!

First, that is a very large pool, I can not recall many we hear about that are that big. The recommendation for sand filter size comes from ANSI/NSF 50 Specifications for public pools. The larger the filter the less frequent backwashing needed. Also, some pools have more to filter out then others and we want to make sure that we are recommending big enough to make it trouble free for most situations.

 

[y_not]

Re: Looking for used sand filter - questions.

MAS985 says her size pool, assuming it was 50,000 gallons, which I'm pretty sure it was based on its dimensions and at the least no less than 40k gal. Says you'd need a filter with a capacity of 9.3 sq-ft of filtration area. That seems like utter insanity!!!

First, that is a very large pool, I can not recall many we hear about that are that big. The recommendation for sand filter size comes from ANSI/NSF 50 Specifications for public pools. The larger the filter the less frequent backwashing needed. Also, some pools have more to filter out then others and we want to make sure that we are recommending big enough to make it trouble free for most situations.

Yeah, it was a monster of a pool. I have seen a few users on here with pools this size. I know someone has a 50k gal pool. Maybe the guy that used to have the military salvage one??
It'd be cool to see who has a pool this big and what sort of filter they have and if they get away with it or not.

She (my aunt) doesn't live there anymore, moved out last spring, so I can't go measure it.
I think I posted a picture of it here, at some point, looking south off the 2nd story deck @ the north end of the map.

I'm dying to know its size...
So I did the next best thing. I went to Google maps and zoomed in on her, then used the ruler to do a scale conversion and measure the pool from point to point.
It's a bit of an odd one, as you can see here. http://goo.gl/maps/hYCH1
*Switch off 45deg view in the drop down on the right, that way you can see the full pool in an overhead 90deg view.

The shallow end is 21ft wide and the deep end is 19ft wide. Full length is 40ft (1/4 Olympic lane length).
Shallow was designed with a high focus on kids, so instead of only a narrow 4ft deep area for them to play in, it's nearly 20ft. That's because it starts out at 3ft deep and has an unusually gradual slow grade downward. By the time it reaches the point where the width narrows, it's maybe 4ft deep or a bit more.
Then the deep end doesn't have a gradual hopper, it's about a 70deg slope, in about 1ft out, it's BAM! 8ft deep or so. Then a gradual slope from there down to about 10ft. near as we can recall for depth. Someone in the fam measured it, that's what I can recall.
Pool calc says it's just shy of 40k gal and I figure with the way it's designed in the depth delineations, it's probably right at or slightly over 40k gal.

The thing's up on the market and it's cheap, last I checked anyway.

 

[y_not]

Re: Looking for used sand filter - questions.

I finally found a sand filter that it looks like I'll be buying locally.
It's a 22" Sand Dollar, judging by the date code at the start of the S/N on the multiport, it was made in May of 2005. So 2mo. shy of 8 yrs. old.

He pulled it off of a pond on a property nearby.
Seeing as I'm sure it'll need some gaskets and a little TLC, I told him they were selling for about $75 in the valley. He wanted $200 for it, but didn't really know what they were worth. I told him I could get one from Amazon for $300 /w free frt.

So we negotiated and settled on $75. Honestly I would have prefered $50 for it, since it's so bloomin old. But then again it still has the sand in it, so that saves me a bundle.... if I can re-use it.

Is that a fair price for it...?

So what do you think, will I just need to take apart the valve, inspect and lube it?
Or is it maybe hitting that point where it's o-ring/spider gasket replacment city?

Here are some pics.

[attachment=2:14gboxrl]SD22-05-1.jpg[/attachment:14gboxrl]
[attachment=1:14gboxrl]SD22-05-2.jpg[/attachment:14gboxrl]
[attachment=0:14gboxrl]SD22-05-3.jpg[/attachment:14gboxrl]

 

[y_not]

Does anyone have any input on my filter find?
Should I take it or leave it?

Thx.

 

[linen]

Assuming that is the SD60, then it looks like it can be bought new for ~$280 online. Hard to say from the pictures, but it looks like it has seen some wear...but if it is in good shape, I would think it is worth $75. If it does not work out, at least you are not out too much.

It would be good for pools up to 12500 gallons.

If you buy it, I would not transport it with the sand in since this can damage the laterals (and your back).

 

[y_not]

$280? WOW! Where'd you find that? Not like it's a huge difference, but it's a bit less than the cheapest I could find on Amazon @ $299, which is a warehouse deal. Slightly damaged box kind of thing.

Ooooh, transporting /w sand in it is bad huh?
Good thing I posted here about it, because I was going to haul it with the sand in it. I can't find any suppliers of it here. The pool stores either don't have it and have to order it... SCARY!! Or they want an arm and a leg for it.
Lowes is a no go, they ditched all their pool stuff here, Home Depot too. I'll keep looking, but it's not looking good for a sand source.

The seller said he transported it with the sand in it, not sure how far he hauled it.

Now I'm really wondering if I should dump it and inspect the laterals, only problem is I think the best way to get it out from what I have seen on here is with a shop vac. I presume turning it on its side and dumping it out is bad, yeah?

In what way does it damage them, just breaks some of the grid holes on the little tubes that stick out of the center shaft, or does it actually snap those off the center shaft?

 

[Bama Rambler]

If he's already moved it with sand in it, I'd definitely take it apart and closely inspect the laterals. It can crack or completely break them off. If you can't get the sand out I'd pass on it unless it was less than $50.

 

[y_not]

What are the do's & don'ts of getting the sand out of it?
Really I guess it just boils down to... are there any DON'Ts?

IE. Can I just dump it on its side and coax it out, then when it gets empty enough, turn it upside down & shake gently while coaxing. That sort of thing?
Or is that bad and only a shop vac or a cup, one load at a time will work?

 

[jblizzle]

I would think the only safe way is to vacuum it out.

 

[Bama Rambler]

The issue with turning it on it's side is the load placed on the laterals as the sand shifts across them. You just can't be sure it'll flow across them smoothly. There's a chance that nothing will happen and it will be fine. There's also a chance that the sand will stick and slough off at the worse possible time and break a lateral or more. Oh yeah, once you turn it over and break something, you bought it!

 

[y_not]

It's my experience most people probably aren't going to let you do anything like this to inspect it before buying. It's kind of like, you can take the car for a spin, but you can't take the oil pan off the auto tranny to inspect it for metallic parts, bits, shavings or dust level. You get the idea.

I'm kinda thinking I'm not even going to bother with this one. He lives over an hour away, round trip, slightly up in the twillies. I'll probably spend $20 in gas getting there, lots of steep grades and such, the V6 eats gas on those. $75 wasn't too bad, a bit more than I wanted ($50), but I was feeling generous and the pickin's are slim here. Now that I have to do all this, only to possibly find out there may be a hosed lateral, or 2 or maybe the thread mounts on the bottom of the stand pipe, etc.. I'm tending to shy away from her.

DARNIT! I wish there were more of these around here. This is the 1st one I have seen all year.

Sorry, i'm just venting and grumbling. LOL I apologize.
Thanks for letting me vent.
I envy those of you in pool country.

Tell me I'm not crazy?

 

[y_not]

I went ahead and told him I was going to pass on it, on acct. of the hour trip and having to drain it to inspect, etc... He's got someone else chomping at the bit to buy it, so it's no loss for him.

I did find a Tagelus 100D 600lb filter somewhat nearby, it's a bit of a trip. But it's a pool pro selling it, pulled from a working setup and was functioning at the time. He says the lats look OK, but he didn't take them out and inspect them, just looked them over from the top. So of course no guarantees. But the individual lats aren't too expensive so if i have to replace a few it's no biggie.

It was made in May of '07, oh and it's a top mount /w a 2" multiport instead of the usual 1.5".
I see their side mount allows for the use of 150lbs of gravel & 450lbs of sand. This one appears to be all sand, 600lbs worth. Can I put gravel in the bottom anyway? What are the advantages to doing so?

I know that's a monster of a filter, but it's cheap as heck!! Haven't really decided on a price yet, but he doesn't want much for it and it'll be less than buying a new 20/22" filter.

 

[jblizzle]

Got to make sure you pump is strong enough to adequately backwash that big guy.

 

[Bama Rambler]

You can use gravel in that setup just like the side mount option. As JB said you're going to need a pretty big pump to properly backwash that monster.

 

[Big_kid]

I'm on my 3rd(I think?) season with the Master pack entry level system shown at the link below. I replaced the filter last week because I didn't bring it in out of the cold & it froze. My pool is an Intex Ultra Frame 18x48. I don't remember where I came up with the 7600 gallon figure, but my chemistry results seem to support it. It does all I need it to do, including clean up the green swamp I let it become. I can vacuum easily, backwashing takes 30 seconds. Regular head pressure is 11PSI, and it takes only 50 lbs of sand. I've already saved a bundle on not having to buy those little paper filters. I don't know if it's large enough for your needs, but I wouldn't hesitate to buy another filter from the same manufacturer.

http://www.columbiapoolproducts.com/sto ... layout.pdf

 

[y_not]

Hrmmm... an interesting point. I didn't think about backwashing it.

So will that 1HP - 2 speed Hayward Powerflow Matrix cut it?
I have no idea what the head loss will be, but it has been said it'll be very low since it's an AGP.
Hayward shows @ 10ft of headloss it'll do 86gpm.
The filter's designed flow rate, which from what I gather is more of a max not to be exceeded than anything, lest filtration suffer. Is 100gpm.

So is that a problem?
I could step up to a bigger pump if need be, since I'll be saving so much money on the filter.
I found the SP15922S (1hp-2spd) for $264 /w free freight. The 1.5hp 2spd, model: SP15932S is only a whopping $10 more!! But of course that means more power consumption over the life of the pump, so it costs more there in the end as well.

Thank you so much for all of your great knowledge and advice. It is very much appreciated.