Personally, I think its a big conspiracy among the equipment manufacturers. I believe that the reason sand filters are hardly EVER installed here is because they are so low maintenance. There's no stuff you have to regularly buy. You don't have to get new cartridges filters ever year. You don't have to get a replacement o-ring every 6 months because the POS stretched out. You don't have to get DE at the pool store all the time. You just backwash and get new sand (probably from home depot) every couple of years. Sand filters aren't profitable for them.

In my experience most homeowners are pretty lazy and could care less what type of filter was installed as long as its easy to work on. Whats easier than turning a valve?

What do you think TFP?

(BTW I'm only referring to residential pools here. It seems that DE is the norm with sand being second in the commercial world.)

Nope, I don't agree. I'm in central Florida and I specified cartridge. If you properly maintain it, you should be able to keep the same filter at least 3 years (this is my 3rd and it still looks and works great). Also, if you are careful and lube the o-ring, it should last many years.

I grew up with a pool with a sand filter and the reasons I picked cartridge is because it has a smaller footprint, you'll never accidently get sand in the pool, and best of all, I'm not wasting lots of water and chemicals flushing it out.

If there is any conspiracy, its with the pool builders who I'd argue put in the cheapest filter they can - since as you said, most pool owners don't know the difference. And I suspect that cartridge filters are the cheapest.

Just replaced my sand filter and original sand after 26 years. No maintenance has ever been done (except for backwashing, and replacing the pressure gauge when it rusts), and it was replaced only because the drain pipe on the bottom cracked, and no replacement could be found. Water has always been very clear. The only disadvantages I can see with a sand filter are larger size, and the need to jettison some water when backwashing every week or two. Here that is not a problem, as replacement water falls from the sky regularly, and I always have to remove, not add, water. Also, we have wells and a high water table, so water is free and plentiful, anyway. I could see that drier areas with expensive or restricted water could favor the other filter types, but here, there is really no other choice. The only cartridge filters I have ever seen in this area are for hot tubs or Intex pop-up pools, and I have never seen a DE filter on a residential pool here in Eastern Canada.
Judging by the amount of watering I saw going on when I visited Disney World in Sept., you don't seem to have any water shortage there yet, so I would conclude that your conspiracy theory may have some validity, although I understand that Central Florida has suffered droughts in the past, so the reasons may be historical.

I have a cartridge filter and love it. I don't clean them but once a year in the spring and my pool is open year round. I'm on the 5th year with the original carts and they still look good.

I see you have the Jandy 340. That filter gives me nightmares .

I remember having to clean a customers' filter who had one. I took off the air release and set it aside and proceeded to clean the filters. Once I was done and put everything together, I couldn't find the air release nut anywhere. After some profanity and lots of sweating in the FL sun, I decided to take it apart thinking that it might have fallen in. Sure enough, the air release nut dropped in the filter and was all the way in the bottom of it . I put everything apart again only to have the gasket not seated right causing the filter to leak. After a third attempt at putting together did everything work ok .

Sounds like it really wasn't the filter so much as it was the maintenance guy.

Sand filters are much cheaper than cartridge filters in my neck of the woods.

I have had both and prefer sand

I am SO jealous. I clean my cartridge twice a week

From personal experience, replacing an o-ring on a cartridge filter is a lot easier, quicker, and cheaper than having to replace a gasket seal on a sand filter. Also, as stated earlier a cartridge element can last years. If you should need to replace one, again, a lot cheaper and easier than having to fix/replace a broken lateral. We inherited a sand filter and in the first year alone I had to replace 2 gasket seals, a lateral, and replace the sand. Cost me close to $200, not to mention the hours spent taking everything apart, and re-balancing the pool chemicals afterwards. I ditched the sand filter after that first year, and got a cartridge. In the five years since, we are only on our second element, and have had to replace a body o-ring on it. $60 for the element, $12 for the o-ring. And both took literally minutes to replace. Some have mentioned that you can't vacuum to waste with a cartridge filter, but I installed a pvc valve between the pump and filter alleviate that problem. The only regret I have about the cartridge purchase is not doing it sooner. The money I spent fixing the stupid sand filter could've gone towards the cartridge purchase

Replacing seals on a sand OR cartridge is not a common practice and should have little impact on the NEVER ENDING debate of which type filter is best.

My sand filter is 7 years old and I have never done anything but backwash it and replace a pressure gauge I left on it one winter. That doesn't mean sand is better, it means that we all tend to favor the type filter we currently own.

I have been working in the industry in Central Fla for awhile.

I know Florida is a unique market with respect to swimming pools, (excepting so. Cal & AZ)
due to high avg water temps, and long natural swim season.

Basically, sand filters are the least fine variety of filter (adding Zeolite, or DE to a sand filter notwithstanding)
So, they will leave more organic debris in the pool,
which means more work to maintain.

I believe that a sand filter precoated with DE or Zeo type filter media to be as effective as a cart or (maybe) DE, but that is just not that common.

Oddly enough, EcoSmarte is the biggest proponent of sand filters with Zeo media.

Also, algae is a given in Fl, and it takes much longer to clean up with sand.

-B.

Algae is prevented in a pool (and removed from) through the proper use of chlorine. The filter you choose should have no bearing on your ability to maintain algae-free water

I know I am (sort of) not welcome, in a hospitable way here, being a lifetime PS guy...

But, I have been lurking here for over a year, before creating an acct & posting,
and want to be gentle here, so as not to offend the powers that be here.

That being said,
If we leave more organic material in the water, we will need more sanitizer to offset that, no?

I am of the impression that Filtration, Circulation, and Sanitization are the 3 points to clear water, and more or less of one will require more of the others.

-B.

Jetta,
You're welcome here.

Yes, more organics will create more chlorine demand. I'm not sure what your question is regarding the 3 points to clear water

I'm not in Florida but when researching my pool buy I seriously considered a cartridge but came to the conclusion (I'm not implying right or wrong) that sand would be easier and more cost effective. I've never had a cartridge filter and I've only had my pool for 1 year - but my personal research led me to conclude that sand was what I wanted.

I seem to recall some people here saying that good old sand has been around for decades and works just fine. After all the options and bells and whistles and upgrades (and COSTS) of a pool purchase I suspect I started thinking "just give me good old proven things that work".

That said, if the pool I ultimately wanted (and bought) only came with a cartridge I still would have bought it.

If you think about it none of the filters remove organics from the water. They stay in the fluid path until you clean the filter so it's the Sanitizer that does the work in all cases. The sand filter might leave a minute amount more organics in the water after cleaning but that's only if you cleaned the cart or DE perfectly and even then it wouldn't be enough more to tell.

Trouble I see with sand filter is they only become a "polishing" filter Once they partly clogged. Depending what they are clogged with (organics) Your chlorine use will go up.
I prefer some thing where frequent cleaning DOES NOT lower the nominal filtration too much, but hey everything works better dirty.

acd,

Welcome to the forum. I am having trouble understanding your post. Could you clarify? Seems to me chlorine usage will be essentially identical regardless of the type filter. I also don't understand the "polishing" part.

What I mean is the nominal filtration level goes down the more clogged a filter gets
When new lets say you filter 10 microns when clogged you filter 1. Random non scientific numbers just giving example

With sand filter they tend to start out with a higher micron level while some cartridge can start at less then a micron ... Not normally seen in pool industry ...

You can clean a cartridge filter more often with out having a large impact on performance while a sand filter you can not
By more frequent cleaning you are removing the organic matter from the water before it continues to break down.

Some times pool haze is cause by particulate and is why de filters "make the pool sparkle"
Again not the biggest issue but it's the only advantage i see of a cartridge filter.


To sum up it's the relationship between organic buildup and filtration capability and how often you can clean while maintaining high filtration.