What filter to choose...cartridge or DE

[Ready2swim]

We are beginning our new pool next week and the company building it for us has suggested a cartridge filter instead of a DE filter...I have always had DE in the past but this guy seems adimate that a cartridge filter is less hassle and works just as good??

I am sure there will be some opinions here...HELP!

[Bleach=Chlorine?]

Most people will agree that all three: sand, DE or cartridge have advantages and dis-advanatges. It is basically a comparison of the amount of work you want to do vs the filtering quality you want. DE filters down to ~5 microns but most people also consider it the most work. I have a DE filter and don't mind the work -- of course I have an area to backwash the DE into where it won't be a huge pain.

[CarlD]

You will either LOVE:p or HATE:mad: a cart. Builders like them because they are maint free for the first season...THEN you have to clean them:eek: So builders push them, not because they are better for you but because they are better for THEM. You have no problems before the warranty runs out. Plus they don't have to run all the plumbing you need for sand or DE to backwash them. That doesn't make carts bad. There ARE tricks to make them easier to use.

I had a little tiny cart on an Intex and hated it. I now have sand and wouldn't have any other--well, maybe DE. But my dad had DE for decades and wouldn't have sand or a cart.

Your builder doesn't have to live with your choice--you do. Make the choice that YOU can live with.

[ThePoolGuy]

DE all the way baby!!


I really don't have much experience with a cart but I have cleaned one once. It's not a bad deal to do but I really perfer the DE because of how clean it gets the pool. As for the maintence of a DE, it's not that bad...now cleaning one is more work than a cart for sure. Even so, I think it's worth the extra work. You also have to add DE each time you BW but you don't have to BW but like once a month and or if the start pressure is higher than normal. The sand filter would be my next choice after a DE filter. If you choose a DE, check into if you can BW into the drain, I've read some areas get picky about the DE but now sure if it's true or not.

edited: don't you have to clean a cart filter once a week or something like that? A DE is about once a year.

[BigSplash]

Sandfilter with a cup of D.E. medium added to the scimmer after each backwash :D :D :D

[jereece]

I have use a cartridge filter with my 27' AG pool for 6 seasons now. I like it. It provides good filtering. I only need to clean the cartridge about once a month. It takes about 20 minutes to clean with a garden hose. At the end of the season, I clean the filter real good and store it in a box. This way I can bring my filter housing and pump into the garage and store it over the winter. A cartridge lasts me about 3-4 seasons. Years ago I had a sand filter with another pool and did not feel that the filtering was as good. So I am happy with my cartridge.

[waterbear]

First let me say that I favor cartridge filters. Now on to some USEFUL info to help you make a decision. (or my filter choice rant, if you prefer to call it that!:rolleyes:)
DE will filter to about 6 microns, Carts to about 20....Not too shabby, IMHO
A PROPERLY SIZED cart is not a lot of maintenance, Hose off the cart once a month (10 minutes), soak it yearly (overnight)
DE needs to be backwashed or broken down to be cleaned....a lot of work to break it down plus you have to replace the water lost by backwashing.
A properly cared for cartridge can last 5 years but they can be pricy to replace. DE powder is cheap.
DE powder can cause silacosis if inhaled....need to be careful with it in dry form.
If you want the cleanest, most polished water you can get in you pool get a DE filter. If you will settle for a close second then a Cart is good.
Probably the WORST filter you can get is an UNDERSIZED cart for you pool. Oversize it a bit.
A dirty cart will actually filter better than a clean one (to a point). It can filter down to about 10 microns, dirty DE just stops filtering. A dirty DE filter will cut your flow rate down and cause your pressure to rise much faster than a dirty cart.

Bottom line is both will perform very well if sized properly. DE is a bit more work, especially when you have to break it down, which should be done yearly or more often, depending on how dirty it gets. If the DE filter allows you to backwash (some don't) then that is an option (but not a good one, IMHO. explanation below)

I don't think backwashing a DE filter is a good idea....Can any DE owners tell me what happens to the grids when you run your filter without DE in it?
The grids get clogged with dirt and covered with organics that stick to them and make the DE stick to the grids and you need to break the filter down and clean the grids. Right DE owners?
NOW, what happend when you backwash? You are forcing the water backwards through the grids.....the grids get clogged and dirty with the same organics! Is it any wonder than when you do break down the filter to clean it the DE is caked together on the grids and the grids are clogged? IMHO, when it is time to clean a DE filter it needs to be broken down and cleaned , not backwashed.
Now on to 'bumping' a DE filter....You knock the layer of dirt that is sittiing on the grids and the DE off the grids so the dirt and DE mix together and then the grids recoated with dirty DE. IMHO, this does not make for good filtration. Dirty DE is dirty DE!
Once again I stress that if you want the clearest water you can get then DE IS the way to go....but there is work involved.
Carts are a close second and the amount of work is much less IF THE CART IS SLIGHTLY OVERSIZED for your pool.
If you want the easiest filter to maintain then you want sand. It filters to about 60 microns which really isn't that shabby and backwashing works well with a sand filter. They still should be broken down about once a year and the sand cleaned and checked for channeling.

In actual practice you wll be happy with any filter you pick..All three types do a good job with different tradeoffs. You just have to decide which one is right for you!

[iardon]

DE filter owner here.... man, now I'm all worried about this silacosis thing. :eek:

So... what cartridge filter would you recommend for a 35,000 gallon pool (one pool guy told me it's 40,000) with a 1 hp. pump?

Thanks,

Ilan

[waterbear]

DE filter owner here.... man, now I'm all worried about this silacosis thing. :eek:
Just use commen sense and don't breathe the stuff. The risk of silicosis from DE power is very small but also very real. (and so are the dangers of working with muratic acid and chlorine! Just use commen sense!)

So... what cartridge filter would you recommend for a 35,000 gallon pool (one pool guy told me it's 40,000) with a 1 hp. pump?
Cartridge filters have a maximum gpm residential flow rate. You want to be well below that. For commercial pools the maximun flow rate is .375 gpm/sq. ft. of filter area which is much lower than the maximum flow the filter can handle. You want to be closer to that flow rate. You need to calculate the flow rate from your pump based on the performance graph and find the biggest filter that will operate at that flow rate or slighly higher. This will be a much larger filter than if you went by the residential rating. For example, my pool would only need a 75 sq. ft. filter accoring to my pump size and the residential maximum flow rate but my builder put in a 150 sq. ft. filter which my pump can handle fine also (my pump had to be larger because of the spa than if I only had a pool. If I didn't have the spa I would have had a smaller pump and would only have needed a 50 sq. ft. filter, which, in fact, one builder used in a proposal with a separate filter system for the spa when I was shopping for a pool) If he had gone with the smaller one I would have a much shorter filter run time (time between cleanings) than I do and would probably hate my cartridge filter.
Thanks,

Ilan I know this is a bit confusing but it is the best answer I can give. Sizing a pump and filter is a bit tricky. General rule of thumb for a cart. is get the largest sq. ft. your pump and plumbing can handle efficiently.

[CarlD]

Probably the WORST filter you can get is an UNDERSIZED cart for you pool. Oversize it a bit.

Evan is wrong. The worst filter you can get is an undersized filter of ANY type, Cart, DE or Sand!

If you want the easiest filter to maintain then you want sand. It filters to about 60 microns which really isn't that shabby and backwashing works well with a sand filter. They still should be broken down about once a year and the sand cleaned and checked for channeling.

If you oversize your sand filter and are happy with the performance, this isn't necessary. I would disagree here and say do NOT do this unless you have a problem. Even more, the dirtier the sand is over the years, the finer it will filter--it gets BETTER with age!

In actual practice you wll be happy with any filter you pick..All three types do a good job with different tradeoffs. You just have to decide which one is right for you!

Gee--I thought I said that! ;)

Unfortunately, we don't yet know of any research on the improvement due to adding a little DE to a sand filter. Everyone who has used it has been THRILLED with the results (including me). At night, you easily far less stuff in the water when the underwater lights are on--I'm simply amazed at how clear it now is. All the ease of sand filters, and, apparently, most of the performance of DE filters!

Ah, but if only someone would do some research on the filtering increase...You use FAR less DE in the sand system than you do in the DE. I only backwash every 2 or 3 weeks, and only use about 3/4 of a cup of DE each time--that's about 1/4 to 1/3 of one of those large DE measuring cups!

[waterbear]

I will stick to my guns and say that an undersized cart is probably the worst nightmare....I use the intex pools as a prime example!

As far as cleaning a sand filter..I will also stick to my guns...dirty sand can channel and when it does your filtering perfomance drops down to zilch! Once a year at least stick a hose into the sand and let the water carry the dirt out of it and break up any clumping!

That's what is so great about this forum....we get to disagree with each other!:D

On a final note....gotta agree that adding DE to a sand filter is a good idea...doesn't work with a cart but I have heard that you can add some of that cellulose based DE replacement to a cart and get the same type of effect. Never tried it so I don't know how well it works.

[CarlD]

I will stick to my guns and say that an undersized cart is probably the worst nightmare....I use the intex pools as a prime example!


Evan, you misunderstood me, I think. An undersized cart WILL be a nightmare, but so will an undersized sand or DE filter.
Cart: Torn filter, crap blowing into the pool
Sand: Broken lateral, sand AND crap blowing into the pool.
DE: broken/torn screens or fingers AND DE and crap blowing into the pool.

In all three you need to replace them with a proper sized filter and then you have to clean out the pool..:mad:

I started with an Intex with a little 1/6hp cart. Hated the thing (the pump that is--loved the pool)--just like Evan did. Not because it didn't do the job--it did, with care, but because cleaning the d*** thing was a messy pain. Luckily, I bought a case of filters for about $10 each and I'd make each one last 2 weeks, cleaning it once then chucking it. It didn't keep us from enjoying the pool, just it was one more pain in the patoot.

If your sand filter is properly sized and you have properly backwashed it all season, the dirt and sand will not be a problem. Late in the season you want to make sure your water is super-clean before closing. Then my final water treatment is to push that clean water to shock level and close--my filter is clean, my sand is FINE.

Check with Poconos and see if he's followed your procedure. Bet he hasn't.

That IS what's great about this forum...We CAN be candid in our opinions. Evan and I can disagree and STILL have great respect for each other.

[Ready2swim]

Man...you guys are passionate about your filters !! I knew I would get some sort of detailed answer. Thanks for all of the information, I am still a little torn as to what filter to buy, I dont mind maintenance, but if given the chance to chose of course I would want to do less than I have to...however I would rather do more maintenance than sacrifice water clarity. I want to be able to SEE the bottom of the pool without seeing any floaties or crap in the water...if DE is the only way to accomplish that then I geuss I have made a decision...:confused:

[cruzmisl]

Well you're half way there. You still need to decide on a brand and model:)

Keep us posted on what you decide.

[CarlD]

Man...you guys are passionate about your filters !! I knew I would get some sort of detailed answer. Thanks for all of the information, I am still a little torn as to what filter to buy, I dont mind maintenance, but if given the chance to chose of course I would want to do less than I have to...however I would rather do more maintenance than sacrifice water clarity. I want to be able to SEE the bottom of the pool without seeing any floaties or crap in the water...if DE is the only way to accomplish that then I geuss I have made a decision...:confused:

Nah...Evan and I are just passionate about ARGUING!!!!;)

Remember: ALL 3 FILTERS can give you EXCELLENT performance if you size them to your pump and pool and maintain them properly. There are ways to tweak them (like DE to a sand filter) but which you choose is whatever floats your boat (or your pool raft!). But you must size and maintain them properly or you will be miserable.

[Tredge]

Just to add somthing else to argue about ;)

I use a sand filter with http://www.zeobrite.com/ instead of sand.

They claim filtering down to 3 microns.

Now....I wonder how great it would be if I added DE to my zeobrite.....

Where can I buy DE :)

[waterbear]

Just to add somthing else to argue about ;)

I use a sand filter with http://www.zeobrite.com/ instead of sand.

They claim filtering down to 3 microns.

Now....I wonder how great it would be if I added DE to my zeobrite.....

Where can I buy DE :)
Hate to burst your bubble but water will take the path of least resistance...which will be AROUND the grains of zeolite and not through it! It might filter marginally better than sand but not anywhere near DE....not even sure if it will filter as well as a cart.

[waterbear]

Man...you guys are passionate about your filters !!
If you don't want to start a controversy three things should never be discussed, religion, politics, and the best type of filter for a swimming pool!:D
I knew I would get some sort of detailed answer. Thanks for all of the information, I am still a little torn as to what filter to buy, I dont mind maintenance, but if given the chance to chose of course I would want to do less than I have to...however I would rather do more maintenance than sacrifice water clarity. I want to be able to SEE the bottom of the pool without seeing any floaties or crap in the water...if DE is the only way to accomplish that then I geuss I have made a decision...:confused:
All three types of filters will give you clear water. DE will definately give the most polished water but it is the most work. Sand is the easiest by far and the water quality from it is excellent. Carts fall in between in water quality and maintenance.

As a suggestion, why don't you download and look through the instruction manuals for several makes of each type of filter so you can get an idea of what is involved in normal maintenance and complete filter breakdown and cleaning. This might give you a better perspective on what is involved with each type and then you can decide what will work best for you.

[duraleigh]

All three types of filters will give you clear water.
Waterbear,
give yourself a gold star! Common sense dictates that if they didn't (give clear water) they would soon be gone from the market. I was hoping someone would put some punctuation on the end of this never-ending subject (It's been going on for at least twenty years) and I hope you just did.:)

[ThePoolGuy]

I'm not arguing this but more trying to understand this. You say the sand gets better with age? I thought the sand would get beat down into small particals over time and get spat into the pool?




If you oversize your sand filter and are happy with the performance, this isn't necessary. I would disagree here and say do NOT do this unless you have a problem. Even more, the dirtier the sand is over the years, the finer it will filter--it gets BETTER with age!

[waterbear]

I'm not arguing this but more trying to understand this. You say the sand gets better with age? I thought the sand would get beat down into small particals over time and get spat into the pool?

This is another neverending debate....whether sand needs to be replaced or not....I will refrain from my feelings on this since they do not agree with Ben's or several of the sand filter users on the forum!:D

Dirty filters do filter smaller size particles than clean filters but then the backpressure created becomes a limitng factor....Once again DE is the most limited by dirt, sand the least, and carts fall in between! However, when sand gets too dirty it can channel and that reduces it's ability to filter by a great amount!


If you oversize your sand filter and are happy with the performance, this isn't necessary. I would disagree here and say do NOT do this unless you have a problem. Even more, the dirtier the sand is over the years, the finer it will filter--it gets BETTER with age! Well, I guess this has opened another Pandora's Box! :eek::D

[jereece]

DE filter owner here.... man, now I'm all worried about this silacosis thing. :eek:

So... what cartridge filter would you recommend for a 35,000 gallon pool (one pool guy told me it's 40,000) with a 1 hp. pump?

Thanks,

Ilan


http://www.intheswim.com/Pool-Filters-and-Pumps/Filters-and-Pumps-for-In-Ground-Pools/Hayward-Super-Star-Large-Capacity-Cartridge-Pool-Filter/

[waterbear]

http://www.intheswim.com/Pool-Filters-and-Pumps/Filters-and-Pumps-for-In-Ground-Pools/Hayward-Super-Star-Large-Capacity-Cartridge-Pool-Filter/
Multi cartridge filters such as this one (and the Pentair Clean and Clear Plus) are a chore to clean...you have 4 cartridges, not one! they take longer to break down and assemble also. If you need this large a filter I would go with sand or DE before one of these monsters....just my 2 cents!

[CarlD]

Well, I guess this has opened another Pandora's Box! :eek::D

That's what makes debate FUN!!!!

And how much longer does Poconos have to go before HIS sand gets too dirty and starts channelling??? Nine years and counting!

I'm only on year 4.

[waterbear]

That's what makes debate FUN!!!!

And how much longer does Poconos have to go before HIS sand gets too dirty and starts channelling??? Nine years and counting!

I'm only on year 4. Bet a sixpack that if you clean the sand your water will be even clearer! Anyway, all that DE you both dump in has probably filled the channels!

[CarlD]

Bet a sixpack that if you clean the sand your water will be even clearer! Anyway, all that DE you both dump in has probably filled the channels!

LOL! Is THAT why the storm sewer I backwash to looks like it's limed????

That's a hard-to-decide bet...I use DE in the filter, a skimmer sock, and JUST got my Dolphin back which polishes the water on it's own...
Assuming the bozos actually fixed the thing... "we don't see nuthin' wrong...."

[bryjen]

I have D.E. The pool was finished in the middle of last summer so we only had it half a season. When closing pool for winter it was broke down and cleaned off> Didnt seem bad. Opened our pool at the end april and I just backwashed for the first last week, the pressure had only gone up from 20 (normal) to 22. I backwashed anyway adding the D.E is very easy. When my sam light is on at night the water is very clear.

[waterbear]

If anyone wants to know how good a cart can filter just look at my avitar! Or even better, the pics I posted in the New Pool gallery
http://www.poolforum.com/pf2/showthread.php?t=234
Like they say "one picture is worth......"

[iardon]

Can you post bigger pics of your pool? Your avatar's kinda small. ;-)

Edit... noticed the link added.


If anyone wants to know how good a cart can filter just look at my avitar! Or even better, the pics I posted in the New Pool gallery
http://www.poolforum.com/pf2/showthread.php?t=234
Like they say "one picture is worth......"

[bradjo]

One thing I didn't see mentioned but I could have missed it make sure as part of the comparison you check the cost of replacement cartridges, sand or zeolite and D.E. so you know that information as well.
hth,
Jo

[iardon]

I just bought a 25 lb bag of DE at American Sale for 10 bucks.

Is that a good/fair price? Just asking since that was my first DE purchase.

[Rangeball]

I'd say that's about 50% off around here :)

[waterbear]

One thing I didn't see mentioned but I could have missed it make sure as part of the comparison you check the cost of replacement cartridges, sand or zeolite and D.E. so you know that information as well.
hth,
Jo Sand is not that expensive and some say it never needs replacing. In fact, most of the people in this forum do, including Ben! There are some that will debate this point, however.
DE is dirt cheap (no pun intended...well, maybe a little pun:D) but you need to replace it all the time so it is a continuous expense.
Cartridges are the most expensive but with proper care they last about 5 years before they need replacing so you need to figure the cost over the time period.
Zeolite, IMHO, is not really any more efficient than sand and is more expensive. It 's main advantage is it's ammonia scavaging ability and it is being pushed as the "new miracle" for your pool! Not quite snake oil but some of the claims made for it's filtering ability come close!
There are some other filter mediums such as perlite and cellulose but they are not that commen. They are DE replacements but some can also be used in conjunction with sand and cartridge filters to improve the filtering ability much like DE can.

[Tredge]

I replaced my sand with Zeobrite.....Maybe new sand would have done the same thing but my water IS clearer and I dont backwash 1/10th as often as I did with the sand.

My old sand had pea gravel in it and a Sta-rite tech told me they dont recommend that anymore because the pea-gravel just mixes with the sand over time and the newer laterals dont require the pea gravel anyways.

Looking at the material when I was putting it in....its a lot more course than sand grains and you get the immediate feeling that it would filter better.

I read somthing about "recharging" the zeolite with salt water. Since I have a SWG its recharged all the time so it seemed like a logical fit for my pool.

Its not that pricey considering I wont be replacing it for 5 years or more, if ever. It certainly doesnt filter any worse than sand and I feel better about my filter :)

Oh.....and when it comes time to replace it, the zeolite is half the weight of sand. Considering what a PITA digging/vacuuming all the sand out was that might be reason enough lol.

[waterbear]

I replaced my sand with Zeobrite.....Maybe new sand would have done the same thing but my water IS clearer and I dont backwash 1/10th as often as I did with the sand.

My old sand had pea gravel in it and a Sta-rite tech told me they dont recommend that anymore because the pea-gravel just mixes with the sand over time and the newer laterals dont require the pea gravel anyways.
Really depends on the filter. Some need it , some don't.
Looking at the material when I was putting it in....its a lot more course than sand grains and you get the immediate feeling that it would filter better.

I read somthing about "recharging" the zeolite with salt water. Since I have a SWG its recharged all the time so it seemed like a logical fit for my pool.
Zeolite is an ammmonia scavanger. Salt water is used to remove the ammonia from the medium to recharge that ability. If you are recharging it all the time it just means you have lost the one true advatante of zeolite since any ammonia it trapped will be going right back into your water.
Its not that pricey considering I wont be replacing it for 5 years or more, if ever. It certainly doesnt filter any worse than sand and I feel better about my filter :)

Oh.....and when it comes time to replace it, the zeolite is half the weight of sand. Considering what a PITA digging/vacuuming all the sand out was that might be reason enough lol.
Hope this info is helpful.