Cartridge vs DE Filter

[polyharmonic]

I have a sand filter that is leaking and not cost effective to repair. So I need to replace it. However, it is very low maintenance. All I have needed to do is:

• Backwash every few weeks (takes like 10 minutes each time)
• Replace sand every few years (only done once, had to hire someone to do it for a few hundred dollars)

I am considering replacing it with a cartridge or DE filter. Having read all that I can on it here and elsewhere, here is what I know:
Cartridge Filter:

• Remove cartridges every few weeks, wash off, re-install (takes like 1 hour each time so much more work than backwashing sand).
• Replace cartridges every few years (costs a few hundred dollars but cheaper than replacing sand, I think)

DE Filter:

• Backwash every few weeks but need to replace DE each time. So it takes longer than sand backwashing (20 minutes?) Also I think it costs like $7 to replenish DE each time?
• Clean "grids" once or twice a year. Can usually just pay someone to do it for like $120.
• Replace "grids" every few years. (cost?)

Here is my impression and please correct me if I am wrong.
1. It seems like it takes longest and most work to clean a cartridge filter each time you do it. I mean you have to remove the cartridges, hose them down thoroughly, and re-install them. However, perhaps you don't have to do it as often as a sand or DE filter?
2. Backwashing a DE filter is like backwashing a sand filter but you have to also replenish the DE and is done about as often. So its a bit more work and cost.

For those who have experience and own cartridge and DE with a decent size pool 15k+, how would you compare the cost and maintenance effort of the two?

 

[ZcottD]

Why does it take an hour to clean the cartridges?

I have a DE filter, its not a grid though so its more bump back, ok pressure still bad, take apart and clean, put it back together replace earth deal.

That takes about 45 mins, hoping my new cordless drill drops that down to 30 mins, but I have always looked at cartridge filters as the golden answer, I was thinking 30 mins max to clean them from what I have seen with a proper hose attachment, its like a comb looking thing.

Personally when you have a ton of debris in a pool, DE is a pain to have to clean and change frequently, water looks great but annoying to deal with DE itself, especially the stupid paper containers most companies sell it in. My goal is to move to a cartridge filter and run the pump more often with a lower speed pump, and thus get similar filtering results.

 

[jblizzle]

Some corrections:
You should clean any type of filter when the pressure rises 20-25% over the clean pressure (not weekly, etc).
If you size your cartridge filter correctly, you may only clean 1-2 times per year.
If you size your DE filter correctly, you may only clean 1-2 times per year ... some members never backwash and just do a full cleaning when needed

I replaced all 8 of my DE grids for about $150 ... I think the replacement cartridges for the large cartridge filter like you would want cost a good bit more than that. Either of these should last many many years (5+ easily).

My previous pool had DE. My current house/pool had the same DE filter when we bought it. If I ever have to replace it (doubtful), I think I will go with a large cartridge filter. There are pluses and minuses though.

DE and Sand backwashing can help control the CH rise we have in AZ due to evaporation. BUT, I have a SWG, so that also lowers my salt and CYA which requires me to add more.
Cartridge you do not drain to clean, so you keep the salt/CYA, but the CH builds up faster ... although you can always drain and refill as desired.

I just do not really like dealing with the DE anymore and since I always tear down the filter to clean it, may as well do the same with the cartridge.
Also the cartridge filters have a lower head loss than the DE, so I would get higher flow rates out of my pump for my solar heating.

 

[Deb04]

I have a cartridge filter and, yes, about an hour to take out the filters, clean, and put back together. (Note, as a petite woman, I am neither strong enough or tall enough to remove the filters. I need hubby to do it. BUT, I only have to do it 1-2/year. Our swim season is short in NH. Our pool is open 4-5 months/year.)

 

[chiefwej]

There are two things you can do that may both be more important than what type filter you choose. The first is getting an oversized filter. The second is using hair nets in your skimmers. That cuts down on all but the very finest debris getting to the filter.

I have DE, my son who lives across the street has cartridge, my best friend, who is also my neighbor has sand. With a SWG system I would avid sand. The amount of water used in backwashing tends to change your salt and CYA levels over time. And you have to backwash much more often than you will ever need to service either of the other types. Since I have been always using hair nets in skimmers and knee highs in a leaf canister, I only clean my DE filter twice a year. My son has a pool that's a bit less than 10k volume and has a 425 sq.ft. Cartridge filter. It has four filter cartridges in it. He really only needs to clean it once a year, again using hair nets in skimmers. Given a choice, I think with my SWG pool, I would put in the biggest cartridge filter I could. No wasted water from backwashing and no impact on my chemical balance. But whatever filter I chose, it would be big.

 

[polyharmonic]

Interesting that the consensus so far seems in favor of cartridge filter. However this is from people who currently own DE and (I guess?) don't have personal experience maintaining a cartridge filter.

One thing that was making me shy away from it was the 1-hour needed to remove the cartridges, hose down the cartridges and then re-install them. I suppose it doesn't have to take that long but it would suck to have to do that very often compared to the 10-minutes it takes to backwash a sand filter.

However, it seems that if you buy the biggest cartridge filter possible, you could reduce cartridge washing to a couple times a year??? If so, that would actually be much better than sand backwashing actually! (No way you can just backwash a sand filter 1-2 times a year).

But what is so bad about DE maintenance though? I sounds like if you buy a big enough DE filter, couldn't you just hire someone to thoroughly service it (clean grids, replace DE) twice a year and in effect do no maintenance yourself? And even if completely servicing it yourself, in what way is DE more of a pain to deal with than cartridge exactly? Pouring several pounds of DE down the skimmer every time you backwash doesn't seem like it would be that hard (or maybe it is because you have to drag a big bag of it from your storage to pool and back?). As for washing the grid, well that sounds like about the same effort as washing cartridges but you only need to do that maybe once a year.

 

[ZcottD]

The DE powder is stored in a papery bag, never a good seal, the powder gets airborne very easily and is not good to breathe in. I hate dealing with it, don't have a good mask for it, and I hate storing the stuff. Wish it came in a nice sealable plastic bucket.

If you are gonna have someone else service it, sure go DE, it filters the best. Let the pool guy bring his own DE and deal with it. If you are gonna do it, cartridge would probably be easier.

To be fair to DE, when things are going right, you can go months without cleaning and recharging the DE.

 

[pabeader]

I have a very large cartridge filter. It has 4 seperate filter cartridges in it. I clean them when psi has risen 25%. It takes me between 4 and 6 hours to get them clean. I use hairnets in my skimmer but I do have a bottom drain that is functional so I'm sure stuff gets to the filter that way.
Àfter all the reading I've done, it seems that most folks would like to have somthing different from whatever they currently have. I would rather have a sand filter. I hate the hours spent standing in the driveway in the hot sun. Love the idea of backwashing and being able to add DE if I want that extra sparkle. Since the sand never needs to be replaced, it's a one time expense. Just seems like the best overall option to me. Grass is greener on the other side of the fence? Maybe.

 

[sangree99]

I have an oversized cartridge filter (520 sq. ft. filter in 23k gal pool) and love it! I clean it just once a year. It takes maybe 90 minutes to pop the top off, remove the four cartridges, hose them off with the Aquacomb attached to the hose, and reinstall. I also use hair nets in the skimmer basket. They're dirt cheap on Amazon- like $6 for a hundred. If you size your filter large enough, you may find that your filter pressure never exceeds 25% of starting pressure. Another bonus of an oversized cartridge filter that was already mentioned is the low head: my filter pressure reads zero most of the time, allowing me to run my variable speed pump at very low speed for maximum efficiency. I've never had a sand or DE filter- I went with cartridge because backwashing just seemed like a hassle, a mess, and a waste of water.

 

[harleysilo]

DE here, I like it fine. I store my DE in a small plastic trash can by my pool equipment. I backwash it has needed, takes me about 10 min to backwash and recharge. I clean it once a year. This involves one large nut on a metal band being loosened and then the top lifts off. Next I place the grids in a trash can full of soap and water. I let it sit overnight and then spray off with hose next day and reinstall. Hosing off takes 20 mins or so.

 

[duraleigh]

Most pool owners like the type filter they are used to. Sand seemed to work well for you, right?

I would be cautious changing to something different. "If it ain't broke, don't fix it"

 

[polyharmonic]

DE here, I like it fine. I store my DE in a small plastic trash can by my pool equipment. I backwash it has needed, takes me about 10 min to backwash and recharge. I clean it once a year. This involves one large nut on a metal band being loosened and then the top lifts off. Next I place the grids in a trash can full of soap and water. I let it sit overnight and then spray off with hose next day and reinstall. Hosing off takes 20 mins or so.

What is your exact make and model of DE filter?

 

[chiefwej]

I've quit backwashing my DE filter. Since I only have to service it once or maybe twice a year, I just do a break-down cleaning each time. It takes only a little more time than it takes to clean the cartridge filter, that my son has. It's really just the same process, with a little more time and mess with the DE.

 

[Bandit5]

What is your exact make and model of DE filter?

Although I am not harleysilo, his post it is eerily similar to what I may have wrote. I too store DE in a small plastic trash can. I don't soak my grids though, I just hose them off.

I have the Pentair FNS Plus 48. Though I will shortly replace the drain plug with a ball valve to make it even faster.

 

[harleysilo]

What is your exact make and model of DE filter?

Hayward DE4820

 

[polyharmonic]

I've quit backwashing my DE filter. Since I only have to service it once or maybe twice a year, I just do a break-down cleaning each time. It takes only a little more time than it takes to clean the cartridge filter, that my son has. It's really just the same process, with a little more time and mess with the DE.

Is this because your unique situation allows you never backwash though? That is your PSI doesn't rise and your use of nets on baskets means filter is much less clogged than others?

People remark that washing cartridges once or twice a year is possible. So it seems at least to be not that unusual. So I wonder if never backwashing a DE is really possible and if so, what circumstances would make it so?

Also besides washing the grids, what else is entailed by DE breakdown cleaning? Do you replace all the DE as well I guess?

 

[jblizzle]

The biggest factor is maintaining proper chlorine levels so you don't get algae starting. And using the skimmer socks to prevent debris getting to the filter. Also using a robot cleaner instead of suction clear helps too.

 

[JoyfulNoise]

Pentair QuadDE-100 on a 16,000 gallon pool/spa. I only tear it down and clean it out twice per year .... BUT, last year, I got too busy to do my normal Fall cleaning and it went an entire year without cleaning it or backwashing it. Pressure increase barely reached 25% over clean pressure and the flow from the returns and my spa spillover was unchanged. Absolutely no issues with my chemistry and sanitation staying balanced. Water clarity remained perfect the entire time. Cleaning involves pulling out four cartridge style units that hold the DE and rinsing them off as well as cleaning out the body of the filter. Takes about 2-4 hours on a Saturday morning...not really a chore at all.

If you oversize any filter, it dramatically changes the amount of "maintenance" required. I would not hesitate to get another DE filter for my pool just as long as I can get the biggest one possible....

 

[chiefwej]

I use knee high ladies nylons in a leaf canister and hairnets in my skimmers, so no water gets to the filter that hasn't been strained through at least one of those. That means very little debris ever gets to the filter. I also have a VS pump and that means my filter is usually running with low flow and low pressure. That combination means I am able to go much longer between between cleanings. Since I do it so infrequently, I try to do a thorough job. In the past, doing backflush and recharge, I found it difficult to judge just how much DE to put in. I know the rule of thumb is 80%, but doing so I sometimes found at the next breakdown it was over filled with DE. The amount that I would actually expel when backwashing seemed to vary. So, to be consistent, I decided to just eliminate the backwash recharge cycles and always breakdown clean. Once or trice a year, not a big deal.

 

[polyharmonic]

The biggest factor is maintaining proper chlorine levels so you don't get algae starting. And using the skimmer socks to prevent debris getting to the filter. Also using a robot cleaner instead of suction clear helps too.

If you did have an algae bloom or swampy water though, I wonder if cartridge might be the worse? I know for sand you have to backwash constantly. Doing the equivalent for cartridges might be taxing.

Even DE might be easier in that case, no?

Anyone with experience with cartridges when pool is green or worse swampy?