Switching from a cartridge filter to a sand filter?

JimMarshall

Gold Supporter
TFP Guide
Jun 5, 2017
1,003
Oil City PA
Is there any reason I shouldn’t?

Went to the pool store today to get an o ring for my filter, and the store can’t even get them anymore. The warehouse doesn’t even carry them, nor does it seem any parts for the filter. I found the o-ring online, so crisis averted there... but I’m thinking I should perhaps look at replacing the filter as a preventative measure before something happens and I’m up dirty pool creek without a filter. I’ve always disliked my filter as the housing is fiberglass and I end up itchy at times after handling it to clean.

Guy at the pool store recommended a sand filter over a new cartridge on the grounds that 1: it is easier to clean, 2: the multi port valve makes it easy to drain water off the pool which is something that I frequently do with all the rain we get, 3: initial cost to purchase and cost of ongoing filter cartridge replacement, etc make the sand filter the more affordable option, and 4: I can use DE to actually give me even better filtration results than I get from a cartridge.

Is any of this the wrong way to think about it? Is there any glaring reason that I should not get a sand filter when I’m used to a cartridge filter?

What size sand filter should I look at and are there any brands to stay away from?
 

JimMarshall

Gold Supporter
TFP Guide
Jun 5, 2017
1,003
Oil City PA
Well this gives me some information that I already knew and some I hadn’t considered.

I was more wondering if there is anyone out there that had made the same switch and regretted it?

A few more questions- how do you properly size a sand filter? This is something that I haven’t come across yet.

A sand filter inherently has much less “filtration area” than a cartridge. Does this mean that a ~4 square foot sand filter would need cleaning 25 times as often as a 100sf cartridge? I’m assuming no or no one would use them but it’s a question I need to ask.

Is the filtration efficiency of a sand filter with de added roughly the same as a de filter?
 

Donldson

TFP Expert
LifeTime Supporter
Jun 12, 2009
4,585
NW Ohio
I switched from a cartridge to sand and am really happy about it. I switched because my fiberglass was also breaking down, I had begun wearing disposable gloves when opening it. The funny thing is that despite the filtering the sand has actually improved my water clarity better because: A. My filter is more appropriately sized for my pool and B. Because it is easier I rarely put off cleaning when it is needed.

With my own experience I personally don't buy in much to the better filtration of cartridges or DE over sand. I don't mean that I don't believe they filter more fine particles, they do, only that such filtration is almost universally unnecessary for TFP clear water if the chemistry is correct. I rarely use DE in the filter unless it's after a swim we kicked some stuff up (I don't vacuum nearly often enough) and I want to polish that off quickly.
 
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Wobblerlorri

Bronze Supporter
I just replaced my cartridge filter with a sand filter and I couldn't be happier. Circulation in my pool is vastly improved, I was able to install a through wall skimmer, which is keeping my water much cleaner than the over the wall Intex skimmer. I'm going through a SLAM right now, and the new filter is doing a fantastic job of keeping the brown dead algae off the floor.

Plus I can now use a suction vacuum instead of the water powered vac! Sand filters and properly sized pumps are well worth the price.

Most pumps will say, somewhere in the product description, what size pool it can be used for. For instance, my pump is 0.5 hp, and is rated for up to 12,000 gallons. You would need a minimum of 0.75 hp, and possibly go up to 1 hp. My little half horsepower pump really sends the water flying around my pool!

Good luck with your deliberations.
 

frogabog

Gold Supporter
LifeTime Supporter
Jul 16, 2010
2,833
Portland, Oregon
While yes, you do have to clean the sand filter more often, it's a much easier clean than a cartridge filter. It used to take me close to a half hour to clean all the pleats on my dad's 3' filter, while backwashing my sand filter every week takes all of about 5 minutes. I'm also not wet! I'd much rather spend 5 minutes a week than 30+ wet annoying minutes 2 or 3 times a year spraying out those pleats.

I say go for it. And get the biggest filter you can afford. Bigger is always better.
 
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JimMarshall

Gold Supporter
TFP Guide
Jun 5, 2017
1,003
Oil City PA
The only thing I'll add is you'll have plumbing changes going to a sand filter. But for AG should not be a big deal.
I figured I would have plumbing changes no matter what I do for a new filter. The chances of finding anything to match my existing plumbing I figure are about equal to the chances of winning the lottery. Lol
 

JimMarshall

Gold Supporter
TFP Guide
Jun 5, 2017
1,003
Oil City PA
Ok, think I am looking at a 24-26" filter, 300# or so..... I see pentair makes several different lines of them, can anyone outline the differences? Sand dollar VS Tagelus?
 

Newdude

Well-known member
Jun 16, 2019
4,472
NY
I'd much rather spend 5 minutes a week than 30+ wet annoying minutes 2 or 3 times a year spraying out those pleats.
Personal preference is KEY here, but I prefer 60-90 minutes a year playing in the wet hose. 5 min backwashes add up to 4.33 hours with a year round season, or 2.16 hours in a half season. I keep compairing it to cars there are millions of Chevy people, and millions of Ford people. (Or insert 2 other brands). Everybody has their favorite, but nobody is particularly wrong.
 
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MyAZPool

Gold Supporter
Jul 3, 2018
1,539
Arizona
JimMarshall
I have had both a cartridge filter (not one of newer one's that I think are much better) and now a monster sand filter.
From my perspective, I like my current sand filter a little better than the cartridge filter that I had way back in the day. I certainly prefer backwashing versus hosing off the cartridges.
I'm in no way a "filter expert". This is just from my own personal experience.
r.
 

borjis

LifeTime Supporter
Aug 19, 2014
3,304
Pacific NW
Maybe it's just where I live and the vegetation around my pool, but I only back wash like once or twice a year at most.
I hardly ever get to the psi of needing to back wash and a sand filter that is slightly dirty actually filters better.

If I'd bought this house and it had a cartridge filter I probably would have replaced it with a sand filter.
 
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JimMarshall

Gold Supporter
TFP Guide
Jun 5, 2017
1,003
Oil City PA
Personal preference is KEY here, but I prefer 60-90 minutes a year playing in the wet hose. 5 min backwashes add up to 4.33 hours with a year round season, or 2.16 hours in a half season. I keep compairing it to cars there are millions of Chevy people, and millions of Ford people. (Or insert 2 other brands). Everybody has their favorite, but nobody is particularly wrong.
Correct me if I am wrong, but if you're having to clean a sand filter weekly, it would have to be grossly undersized?

I also never feel like I get the cartridge filter totally clean.
 

MyAZPool

Gold Supporter
Jul 3, 2018
1,539
Arizona
JimMarshall
Good point!
For me, I live in the desert (sort of) and I only have to backwash my sand filter two to four times a year. It pretty much just depends on how many haboobs we get during our monsoon season.
An oversized sand filter should not have to be backwashed very often at all normally.
r.
 

JimMarshall

Gold Supporter
TFP Guide
Jun 5, 2017
1,003
Oil City PA
I only clean my cartridge filter 2-3 times a year now, I'd imagine that if I am putting a 2-300 lb sand filter on a 24 foot round pool, I won't need to backwash any more often than I am cleaning my cartridge now.
 
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MyAZPool

Gold Supporter
Jul 3, 2018
1,539
Arizona
I only clean my cartridge filter 2-3 times a year now, I'd imagine that if I am putting a 2-300 lb sand filter on a 24 foot round pool, I won't need to backwash any more often than I am cleaning my cartridge now.
JimMarshall
I would probably assume the same! Only diff is you won't have to take the filter apart and clean grids and put the filter back together. If you plumb a backwash line to wherever you want the water to go, just turn the pump off, turn the filter backwash or multiport valve and turn the pump back on and you're in business. :p That's what I did, so I don't even have to un-roll a backwash hose.
Have a good one and take care...
r.
 
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Rocket J Squirrel

Silver Supporter
Bronze Supporter
Jun 7, 2018
920
Alamo, CA
I would never want a messy filter medium like sand or DE. Cartridges are easy to clean. I do it twice a year, but could probably get away with once a year if I weren't (overly?) concerned about the small amount of decaying organics rotting away in there for a whole year. The only hard part is getting the filter tank halves re-assembled and tightening the belt clamp exactly right. But I believe other filter types use similar clamps.

I can't find a reference, but I believe that only cartridges are allowed under code where I live in California drought land. The reasons are (1) backwashing is considered a waste of water and (2) only rain water is allowed to enter the storm drain system.
 

YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
14,557
Evans, Georgia
Only backwash when the filter pressure raises 25%. That's TFP guidelines. Some folks also use skimmer socks which go a long way in helping keep the sand filter (or any filter, really) cleaner.