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View Full Version : Sand Filter or Cartridge?? Which is better?



Aranon
04-23-2006, 02:53 PM
I understand a cartridge is suppose to be easier maintain and filters better than sand. But now I hear people saying, yes thats true but only when they are barand new. I'm finding out people are spending hours cleaning their cartridges. And I also am hearing they some are having to clean them every two weeks or more. Not the once a season like they advertise. Some say they can never get their filters clean after awhile and have to buy new ones to get that really clean look like they did when they were new. Washing my filters once a month for at least an hour or soaking them overnight in acid seems like a lot of work. Surely a sand filter is not that much work.

I have even got a reply that after two years, one guy was going to get rid of his cartridge filter and buy a sand syste.

So whats the deal. Am I only hearing the horror stories and not hearing from the majority, or are the horror stories the majority?? Someone please advise me. I am torn between a Cartridge filter system 150 Sq ft. Pentair and maybe now a sand filter. Which should I get for a 18' x 40' Oval 54" Thahitian above ground pools. Please advise me. Thank you.
Aranon

Poconos
04-23-2006, 03:12 PM
On the old forum the pros and cons of all filters were discussed many times. So, let's start the discussion again. I have sand so I'm biased. Never had anything else. In my opinion, sand is the easiest and cheapest to maintain. However it will miss catching particles that the others will catch. Unless you're a total clean freak sand should be adequate. My water has been totally clear however I do get some fine dust or silt in it once in a while and the solution I've been using for over a year now, add some DE. Silt typically comes from my stream fill water. 9th season now and only thing I replaced was the spider gasket in the multiport valve...once. Sand should last forever. When the pressure goes up some, backwash and you're good as new. Again, my biased opinion.
Al

duraleigh
04-23-2006, 03:17 PM
Aranon,

That debate has been endless on this forum and will continue to be so. The sand owners like sand and the cartridge owners like cartridge. Even the ones who have owned both don't seem to have a definitive opinion.

It's not quite Ford vs. Chevy, but it's close.

Okay, Okay, I own sand and I like it best....a cartridge owner will be along soon to sing the praises of cartridges, then a DE guy will chime in on why his is best.:)

Here is some good advice....whichever one you buy, get it bigger than you think you'll need......everything in your system will function better.:) :)

Aranon
04-23-2006, 04:51 PM
Ok, hears a thought. What if I used Both. What if I bought a Sand system and hooked up a cartridge sytem to it. The sand filter and pump system would be hooked up like normal but instead of going right back into the the pool have it run into a cartridge filter to filter out the fine particles and then back into the pool.

This would be like drinking water filtration with a coarse prefilter and a fine (polishing) filter.

The Sand Filter would take out all the big stuff (prefilter) and the Cartridge filter would remove all the fine stuff. This way the Sand Filter acts a a pre-filter protecting the Cartridge filter from stopping up. At least in theory.

Any thoughts on this set up. Seems like it would work. Any one tried this yet.

Aranon

b2001
04-23-2006, 05:04 PM
What if I bought a Sand system and hooked up a cartridge sytem to it.

I'm pretty sure I've seen a post on this forum in the past advising against that.

But here's an idea. I told you I was going to replace my cartridge filter with a sand filter. What I believe that I am really going to do is get a sand filter and hook it up in parallel with the cartridge filter. I would use parallel piping and cutoff valves so that only one filter at a time is on. I would run the sand filter most of the time because of ease of maintenance poconos refers to and occasionally run the cartridge filter for the "polishing".

I'm not sure I would recommend someone buying two filters as a starter because of the costs vrs. the benefits, but I already have a cartridge filter and I'm planning on buying a sand filter. so I thought I would try to take advantage of the perceived advantages of each. Based on my troubles, I'm still thinking that I will be better off with a sand filter, but I know a cartridge would filter out those very fine particles, after the sand has done most of the work - and I already have one.

Poconos
04-23-2006, 05:33 PM
Check this thread. I made comments about adding DE to a sand filter.

http://www.poolforum.com/pf2/showthread.php?t=465&highlight=%28ajs-1%29

Al

waterbear
04-23-2006, 08:21 PM
I guess I will get into the mix.:eek: (these are just my thoughts on the matter, folks! Don't get too bent out of shape if you disagree with me! As Al and Dave indicated this is and probably always will be an endless debate!:rolleyes:
I like cartridges because, IMHO, the are easier than DE to maintain and give almost as polished a water quality (DE filters to about 5 microns and cartride to about 20). Sand will filter to about 60 microns so it will never get the water as polished as the previous two but it is probably the easiest to care fore. I have had cartridge filters on a portable hot tub, my current pool/spa combo, and on numerous aquariums (talk about a gunked up cartridge...probably worse than Biguinide "goo"!)
I have found that a quick hosing BEFORE the pressure climbs up 10 psi as recommended greatly extends the life of the cartridge, I hose mine off about once a month and the whole process takes about 10 minues including cleaning the skimmer basket in the pump!
The cartridge does need cleaning (soaking) when a lot of organics build up on it. I have been doing a bit of reseach on it and have found that many OEM replacement manufacturerer's recommend soaking in TSP and water and one Austrailian spa equipment company recommomds soaking in a bleach solution (which is also what the aquarium filter manufacterers recommend...btw one of the largest manufactuers of aquarium cartrdige filters is Pentair! The frequency of soaking depends on the bioload (scum, oil, etc.)the filter is filtering My spa used to need it about once a year and my aquariums maybe every 4 months,
If there are any scale deposits then you need to soak in an acid bath to fizz them away.
Now if this sounds like a lot of work then just break down, clean, and reassemble a DE filter!. Yes, it is easy to 'bump' them but all you have done is mixed the dirt and the DE and the filter medium is still dirty and likely to restrict water flow. You can backwash them, but IMHO, not a good idea since you have no idea how much DE you flushed out so you really don't know how much to put back in. You run the risk of either not having enough DE in the filter and plugging the laterals with dirt or having too much DE which, in a worse case,can mean having to take the filter apart and literally chop out the hardened DE inside the filter! I admit that is a relatively rare occurance but it does happen!. IMHO, if a DE filter is dirty (and they get dirty enough to restrict the flow through them pretty fast!) it should be broken down and cleaned.
If you don't care about the work involve then DE WILL give you the cleanest water you can get! I am personally a bit too lazy for that and my brother has a DE filter so I have some first hand experience with them too.
(have used them in aquariums also. basically the same on a smaller scale)
Sand is easiest to maintain, Backwashing is very effective, but they are the least effecient of the 3 types of filters at polishing the water. To me a big drawback!
I guess what it all boils down to is to weigh the pros and cons of each type and see what you are willing to put up with!:D
I opted for almost DE water quality and more work than sand but less than DE and don't mind the expense of replacing the cartridge about every 5 years. I also have the most experience with cartridge filters so I am comfortable with them. I know how they will perform and I know what I need to do to keep them happy!

CarlD
04-23-2006, 10:36 PM
I AM surprised...if you backwash your DE filter until the sight glass is clear, then you know you probably have no DE in it. So you add DE, leaving some "room" in case there is some left, until the pressure is where it's supposed to be...and you're done.

And I'm a sand filter guy.

I increase the sand filtering effectiveness several ways:
1) I have a filter clearly rated for a higher capacity than my pump.
2) I have a 2 speed pump I run on "low" most of the time--this increases the difference between the pump and filter and filter is more effective.
3) I add a cup of DE powder after I backwash, enough to raise pressure 4-5 #, no more (see Poconos) which catches more fine stuff.
4) I use "skimmer socks" in my skimmer to catch a portion of the fine stuff there.
5) I run my Dolphin overnight once a week. The Dolphin has as fine, if not finer, a filtering as a DE. It's high-flow, and runs for 8 hours as it's vacuuming, "polishing" the water.
6) I wear out-of-focus glasses so everything is fuzzy and I can't see if the water isn't perfectly clear!;) :D

waterbear
04-23-2006, 11:20 PM
I AM surprised...if you backwash your DE filter until the sight glass is clear, then you know you probably have no DE in it. So you add DE, leaving some "room" in case there is some left, until the pressure is where it's supposed to be...and you're done.

In a perfect world, yes. DE can have a tendancy to "cake" (for want of a better word) on the grids and even if the sight glass looks clear it is possible for there to be quite a bit of DE left in the filter. You add your DE and leave some 'room' but the filter only lost a little of its DE powder. You have now overfilled. Might not show up on the pressure gauge at first. Do this a few times and you now have a MAJOR filter cleaning to do. This scenerio can happen and does. If you have ever had to chip away at the hardened mass of DE that can occur you certainly don't want to do it more than once!

That is why I feel it is better to tear down rather than backwash a DE. You really don't have any control of knowing how much DE is leaving the filter and therefore how much you REALLY need to put back in.
Bumping is really just being lazy, Mixing the DE with the dirt and crud collected and then redepositing it on the grids is NOT the way to give you good filtration. When the filter media is dirty it needs to be cleaned!
Like I said, just my opinion!

KurtV
04-23-2006, 11:32 PM
I'm surprised no has mentioned one of the other favorites in this never-ending debate: Sand filter with zeolite filter medium. The ease of maintening a sand filter with a filtering capability that's better than a cartridge and maybe even better than DE. Can't be beat, right?

(Patiently awaiting post describing arduous zeolite "renewal" procedure that must be performed annually but that no one who actually has this system seems to worry about.)

waterbear
04-24-2006, 12:29 AM
I'm surprised no has mentioned one of the other favorites in this never-ending debate: Sand filter with zeolite filter medium. The ease of maintening a sand filter with a filtering capability that's better than a cartridge and maybe even better than DE. Can't be beat, right?
If you really believe all the manufacturer's hype then PLEASE come into the pool store where I work part time and let me sell you some dual action Pace 3" tri-chlor that will keep algae from your pool and make your life simpler along with some sodium hydrogen carbonate for adjusting your TA ...it's better for your pool than baking soda! :eek::D;):D:rolleyes: (those comments ARE 'tounge in cheek'!)
(Patiently awaiting post describing arduous zeolite "renewal" procedure that must be performed annually but that no one who actually has this system seems to worry about.) Zeolite is great for ammonia scavaging and will probably help to keep choramines down (if you are not using a SWG) but I don't believe it's filtering abiltiy is going to be much better than sand. Yes, it is porous like DE and the pores have a small micron size but the grains are about the same as sand; and water (and the dirt in it) is going to take the 'path of least resistance' which means it will go around the zeolite grains and not through it. DE on the other hand, has a very tiny particle size and when the slurry of DE and water coats the grid, even though the coating is not that thick it is made of of layers and layers of DE the path of least resistance will be throught the porous DE which is what makes it such an excellent filter medium. Even if the water passed around the DE grain it is so tiny that the space between grains is extremely small also.
Actually,I have read through Zeobrites regeneration instructions on their website and they are really no worse than sand cleaning or cartridge soaking (which many cartridge and sand owners don't worry about either!) and is probably only a yearly procedure also. The biggest difference between zeolite and sand its that while sand is only a mechanical filter medium, zeolite is both a mechanical AND chemical filter medium. People have been using it in fresh water aquariums for years now for these very reasons.

huskerfan
04-27-2006, 04:24 AM
I love my DE filter! Ya it takes an extra 5 minutes to mix the DE powder with the water... but you'll save much more time by not having to backwash as often. I don't believe in "bumping" it either, it's doing it's job, if the guage reads it needs cleaned, clean it.

I'm a little confused - everyone's trying to get DE filtering quality out of your sand and cartrige filters, why not just use a DE filter?? Our local pool stores totally hate and advised against using a DE filter in our state as we have a high iron issue in our water. I can honestly say that that is even more reason to use a DE filter too! There are a few local people struggling to get the iron filtered out of their pools with their sand filters that the local pool store advised them to get, and have rustish brown water while mine is crystal clear. Take care to not inhale DE by all means, but I'd much rather add my DE powder than my muratic acid!

All boils down to personal preference- a crystal clear pool is a crystal clear pool no matter which way it's achieved!

huskerfan
04-27-2006, 04:27 AM
By cleaning it - I mean backwashing it. I think it's overkill to tear it down and clean it each time to me.

matt4x4
04-27-2006, 12:29 PM
Poconos has the right idea - he was the reason I started messing around with DE last year.
Zeolite, zeobrite or zeo anything IS a little better than sand because of the shape of the particles, however, it is not as good as DE, I have zeosomething in mine, but also use DE to "micro filter" and the difference is like night and day!
Before I started adding DE, I could vac my pool all day without backwashing, however, I did notice that after about 25% of the pool was vac'd, you could see the fine dirt pushing back in the return (we have nothing but clay - so the dust in our area is VERY fine).
Once I added DE, after 25% of the pool, I barely had any flow left on the return, so I only do about 10% of the pool at a time if it's really dirty now.
I basically discovered and tested all this during last year's spring cleanup.
Being in the country, I can't vac to waste because we do not have an endless water source, so I have to filter and backwash.
And backwashing with DE really shows just how much dirt the DE collects for you - just amazing, and a really cheap additive to any sand filter.

Billd60
05-02-2006, 01:24 PM
Should sand be replaced? My pool store tells me it should be, but it seems a little crazy to me. Can the sand develop open channels which hinder the filtering? My filter is acting a little funky and small amount of sand is making it's way back into the pool.

roxy
05-02-2006, 05:43 PM
Carl,
Can you please give me some info on the "skimmer socks", this is the first I have heard of them.
Thanks.

CarlD
05-02-2006, 06:17 PM
I see a lot of pool stores have "skimmer socks", or the same thing by another name. They are a filtering bag with an elastic edge that goes into your skimmer basket like a coffee filter goes into a Mr. Coffee, and hooks over the edge. It catches lots of fine stuff that normally would flow thru to the filter itself. You pull it out and rinse it when it gets dirty, replace it when it's worn out. You get 3 to 5 in a package for about $5.

That's it!

ivyleager
05-02-2006, 06:36 PM
I tried out a skimmer sock yesterday and was amazed at the goop it did indeed catch, and only after about 3 hours. I will continue to use it, as well as possibly adding some DE to my sand filter.

CaryB

roxy
05-03-2006, 12:43 AM
Thanks....I will look for them.

gordyjamz
05-29-2006, 10:28 PM
Ok here's my opinion so far reguarding sand. If you don't minda slight haze to your water, I suppose its ok. I'm looking to buy a cartridge. Why you ask, I'll tell ya. We bought our house last year with this pool already here. after two weeks the filter was leaking from the backwash pipe. Needed a new spider gasket. Only 12 bucks at the pool store. OK So I put a new one in, worked fine for the rest of the season. This year it was fine till a few days ago. Guess what its leaking again. It's a hayward swimpro. The guy who sold me the house said he just replaced the sand the year prior(2004). Everyone says the sand should be good for up to 6 years? Well I don't know what to believe. water's hazy. I must say I think i fell for something, because common sense told me " how can water be filtered from sand?" I am still a rather new pool owner who is getting well experienced with addressing problems with algae, filters. etc. And my experience so far is telling me to get rid of the sand filter. Sounds like cartridge is a WHOLE lot easier to maintain. Who can argue with hosing off a filter once a month(10 minutes?), buying a new filter cart. every, what 2 years? versus backwashing, leaking, repairs and such. I may stay away from Hayward too considering the problems with their product. One question I do have for cartridge owners is what size do I get? I have an AG pool 4 1/2 ft, 27 ft diameter round. Hayward 1 1/2 hp pump, 70GPM. Do you also recommend a certain brand other than hayward?

gordyjamz
05-29-2006, 10:33 PM
One more thing too, doesn't all that stuff CarlD wrote (6 steps) for cleaner water with sand filter seem like a lot of money and time spent on a device that's supposed to work properly?

gordyjamz
05-29-2006, 10:34 PM
Ok here's my opinion so far reguarding sand. If you don't minda slight haze to your water, I suppose its ok. I'm looking to buy a cartridge. Why you ask, I'll tell ya. We bought our house last year with this pool already here. after two weeks the filter was leaking from the backwash pipe. Needed a new spider gasket. Only 12 bucks at the pool store. OK So I put a new one in, worked fine for the rest of the season. This year it was fine till a few days ago. Guess what its leaking again. It's a hayward swimpro. The guy who sold me the house said he just replaced the sand the year prior(2004). Everyone says the sand should be good for up to 6 years? Well I don't know what to believe. water's hazy. I must say I think i fell for something, because common sense told me " how can water be filtered from sand?" I am still a rather new pool owner who is getting well experienced with addressing problems with algae, filters. etc. And my experience so far is telling me to get rid of the sand filter. Sounds like cartridge is a WHOLE lot easier to maintain. Who can argue with hosing off a filter once a month(10 minutes?), buying a new filter cart. every, what 2 years? versus backwashing, leaking, repairs and such. I may stay away from Hayward too considering the problems with their product. One question I do have for cartridge owners is what size do I get? I have an AG pool 4 1/2 ft, 27 ft diameter round. Hayward 1 1/2 hp pump, 70GPM. Do you also recommend a certain brand other than hayward?

roddiaz1
05-31-2006, 12:10 PM
I'm thinking of going to cartidge from D.E.. This is my experience: I purchased this house 3 years ago that came with 20' x40' vinyl lined in-ground pool. The pump is a golden hayward (not sure of the specs) and the D.E. filter is a Hayward EC75.

I find that the "life" of my filter is coming to an end. There are a lot of broken plastic parts, non too critical, the pressure gauge sticks, but the filtering ability is no longer any good. Last year I noticed that after regenerating the filter (especially after vacuuming) some D.E. would escape into the pool. Anoying but nothing too terrible. I went through approx. 50lbs of D.E. last year.:mad:

This year (after tearing apart the filter and cleaning it thoroughly) upon opening the pool I noticed that my cycles-time between regeneration-were ridiculously short. About 15 minutes! I noticed that my pressure climbs from 5lbs to 25 lbs, before I even put the D.E. in. when I put the D.E. in it remians at 25 lbs and the only further indication I have a clog is that the water flow back to the pool is but a trickle. I can run the filter with the air-bleed open and no spaying...:p

I called the pool place and they said: Bump and regenerate. I've only done that a dozen times now. I guess I could tear it apart (again) and re-clean it and try agian. I don't know if anybody noticed this yet ,but the EC75 doesn't look like it was designed to be torn apart often...what is it 32 screws??? :confused:

It is true that my water is particularly swamp and gooey this year upon opening, but the filter is on it's last legs I beleive.:eek:

Here is what I beleibe about the cartidge filters. Even if I buy new cartidges every year, it about equal to my D.E. cost (I went through 25 lbs on openning day). And, everytime I replace the cartidges I'll have a virtually new filter. Also, I have several sets of cartidges, so that I can rotate them and while I'm soaking/cleaning one set the other set is working away. I don't think it would be practicle to have several filter nest for the D.E. filter.:cool:

Most of the comparisons I have seen are "ideal condition" operating parameters. We know D.E. cleans best, so let's be more praticle, which system is better when the you've got problems (Algae, tubidity, etc.). Which system is more robust (possibly sand)?

Rod

drumr
06-01-2006, 12:37 PM
I started with a 150 sq ft hayward missle pro cartridge filter when I bought my 24' AG pool and 1 1/2 hp pump. I stuck with it for 3 seasons before changing to a 200 lb poolco sand filter and very recently a 3/4 hp pump that I have been much happier with. I took the advice of some of the other members here and add a cup of DE everytime I backwash and have a crystal clear pool.

The main reason I switched is because I would spend 45 minutes every other week cleaning the filter with a pressure washer (on its lowest setting). I wasn't saving any water by not backwashing because It would take so long to clean even with the pressure washer.

Now I have about the same filtration (with adding a cup of DE) with just a few minutes of backwashing and no bugs, dirt, and other goop that always would end up all over me before I was finished cleaning cartridge.