Recommend a filter

[jlakers]

I am needing to get a new filter. I have a above ground pool, 18,000 gal of water, 1.5 HP pump. I was wondering which type of filter would be the best for my pool. Sand? DE? Or anything else? What do I need to know when buying one of these? Thanks for your help as I am kind of a newbie.

[duraleigh]

Hi,

The filter most people recommend on this forum is the kind they have!!

I would tell you the virtues of a sand filter....Why?....because I've got one and have never owned the other two (DE and cartridge)

I will say that sand does seem to be the most trouble-free type. That said, I'll let others chime in to tell you what's good about theirs.

I think if there was a really definitive answer, the industry would provide that type overwhelmingly.....they don't....it seems to be about an even split.

Dave S.

[mas985]

I have a cartridge which seems to be the least favorite on this and other forums although I am not quite sure why. In my city, I would need to have installed a separation tank to reclaim backwash water in order to pass inspection. Having to clean out a separation tank, which is really just another filter, turned me off to sand and DE as well.

Also, I way oversized the filter so I only have to clean it twice a year and probably could get away with once per year (I don't see any PSI rise in 6 months). To me this seemed like a lot less work than rolling out a backwash hose every few weeks. Down side is I will have to replace them periodically although not sure how often.

[CarlD]

LOL!
Yup, most of us recommend what we have!

I can see why you like a cartridge filter--having to install extra backwash filtering defeats the purpose of having sand or DE.

Rolling out the backwash hose takes a minute. I have reel for it that takes another minute to roll up...no big deal.

I think the antipathy to carts is that when you clean them, it's very hard to do it without getting soaking wet and filthy--to do it right. But there is some sort of system involving a a close-fitting sealing cylinder that you fill with water and (I believe) electric dishwasher detergent. You buy 2 carts, and when one is dirty, you pull the one out of the cylinder, rinse it off, install it, and put the dirty one in the cylinder with fresh water and detergent--but I've not seen this.

Both sand and DE do a fine job as well. DE is a little more work--not much, but it filters finer particles than sand. Sand, however, can last forever, filters better as it gets older, and a single cup of DE powder in it can improve its filtering dramatically. My dad had 20 odd years of success with DE. I have sand and am just as happy. I had a little cart on an EasySet for 3 years and hated it, even though replacement carts were only $10--full size ones run $75-$125 or more.

[waterbear]

Having owned cartridge filters on a spa and now a pool/spa combo for a total of 7 years now (and even longer on large salt water aquariums-they are basically the same-- so I am biased) I can tell you the trick with cleaning them and not getting wet and dirty is to NOT wait until the pressure rises but do it once a month. A quick hose off with a garden hose nozzle set on stream or ribbon (make sure you start at the top and work down the pleats) and the cartridge is clean. Mine takes about 10 minutes total and that includes cleaning out the pump basket and repriming the pump. Maybe once a year I have to soak the cartridge. This regular attention will also help prolong the cartridge life.

The pro and cons of various filters in a nutshell:
DE filters out the most and really polished the water but is probably the most work.
Sand is the easiest but the least effecient at filtering small particles.
Cartridge approaches DE in it's ability to filter small particles and actually will filter better when slightly dirty (which is why some people add a bit of DE powder to them) but the cartridges have a lifespan of about 5 years and can be costly to replace (mine is $110-$165 currently) and if you wait for the pressure to rise they can be a MESS to clean!
I will qualify what I have said by saying that I have never owned a DE or sand pool filter but I have friends with them and I have had to help my brother break down his DE more than once.

[KurtV]

In my web research I found the following general consensus (though by no means unanimous) opinion on filter types:

DE = Cleanest water, between sand and cartridge for maintenance and life cycle costs;
Sand = Easiest maintenance, cheapest over its life cycle, third of three for filtering (but still good);
Cartridge = Most maintenance (but still fairly easy), most expensive over time, between sand and DE for filtering.

All three types have their advocates and detractors (though cartridges seem to have the fewest advocates and the most detractors).

I decided to go with a sand filter filled with zeobrite for the pool we finished recently. The filtering with this setup is supposed to be nearly indistinguishable from DE but provide the ease of maintenance of a sand filter. I've been a little disappointed in the performance as I can see plenty of "stuff" in the water at night with the lights on. I suspect that this is more a function of a relatively undersized filter than of the technology as so many others are quite happy with that combination.

No matter which type you choose, over sizing the filter seems to be universally acknowledged as sound practice.

[jlakers]

Wow! Thanks for all the great information. My current filter is a sand filter, it's old and it seems that a lot of little stuff gets through it.

Anyway, thanks for all of your input.