Considering the move to a sand filter

[denisbaldwin]

While my little cartridge filter (Hayward C12002 Filter with knockoff CX1200RE cartridge) does an alright job, I've been considering the move to sand both to eliminate the constant cleaning of the filter element and to get some improved efficiency through sand filtration. Everything I've read here and other places online is leaving me confused.

Would you recommend sand over cartridge and why?

Would a 250 pound Hayward sand pot work for a 12,000 gallon pool with my 3/4 hp pump?

Other than re-plumbing and putting in fresh sand, what else am I going to have to deal with when converting to sand?

Thanks again for your help, guys and gals. I know I ask a lot of questions, but I'm just trying to do all of this right.

Denis

 

[frustratedpoolmom]

In order of clarity, the Best is DE, second is Cartridge and Third is Sand. Having always had a cart (and things I've read on here) I would not switch to sand, but that's a personal preference I suppose.

What about the cartridge are you unhappy with? How old is the replacement cartridge, and how do you maintain it/clean it? When you say "constant cleaning".... I clean mine maybe once or twice in 5 months of use (once if I'm using skimmer socks). Is your PSI indicating it needs to be cleaned constantly? There could be something wrong with the cartridge if that's the case. Have you had repeated green swamp clearings? Some say this can shorten the life of a cartridge filter.

 

[denisbaldwin]

Answers are in-line.

What about the cartridge are you unhappy with?

It seems it's not filtering fast enough and it gets clogged quickly.

How old is the replacement cartridge, and how do you maintain it/clean it? When you say "constant cleaning".... I clean mine maybe once or twice in 5 months of use (once if I'm using skimmer socks).

I wash it out daily with a water hose and high pressure head. It runs dark brown to clear as I wash it, with a silky sediment of sand and leaf fragments every time I wash. When it washes, it washes back pearly white and then is dark brown again (like a grocery bag) within an hour or so. I use both skimmer socks in the skimmer itself (which I clean every day) and a double sock in the pump hair skimmer, which I also clean daily. The socks I've only been using for the last four days, so the leafy fragments have all but stopped making their way to the filter. The filter is now just filled with dirt and silky-slimy-gross muck daily.

Is your PSI indicating it needs to be cleaned constantly?

After I clean it, pressure reads about 18-19 PSI. Within an hour or so, it's back up to 22-23psi. The next day (24 hours later), I'm at close to 30psi and I clean it. Rinse, repeat. It's been going on like this for the month plus I've been working on it.

There could be something wrong with the cartridge if that's the case.

This cartridge is the third one I've bought for this pool in 2 months. The first two lasted a week apiece, shredding from all of the concrete fragments and the 2HP pump that was overpowering the filter. Once I switched down to a 3/4 hp pump and am down to just the 1/4" or so of sand and and debris in the bottom working it's way out of the pool, this one is holding up. It just gets clogged quickly.

Have you had repeated green swamp clearings? Some say this can shorten the life of a cartridge filter.

This is how the pool looked when I bought the house and started working on it less than 2 months ago:
http://www.troublefreepool.com/how-my-pool-looked-when-i-bought-it-t19316.html

It's vastly improved since then, just down to the bottom dirt/debris which I vacuum up daily... but it's still probably 3-4 weeks of cleaning to get it crystal clear and dirt free.

Sooo.. short of spending the big bucks on a DE filter, I should stick with cartridge?

Denis

 

[baudilus]

Other than re-plumbing and putting in fresh sand, what else am I going to have to deal with when converting to sand?

Bigger particles in your pool water.

Thanks again for your help, guys and gals. I know I ask a lot of questions, but I'm just trying to do all of this right.

That is generally the best way to do things.


OK, facetiousness aside, a sand filter will actually be less efficient than a cartridge filter, and you also have to deal with water loss from backwashing - cartridge filters are the only filters that you can clean without losing water.

I am happy with my sand filter, but your mileage may vary. While cleaning (i.e. backwashing) is easier with a sand filter, I prefer sand's lower TCO (total cost of ownership). There really is nothing that i have to buy repeatedly (except the optional DE / FiberClear / etc. to improve filtering, and water, technically).

That said, I don't know how often cartridges need to be replaced, so there may not even be that much of a benefit.

To answer your question, you would simply need to re-plumb to accommodate the sand filter, making sure to match it's filtering capacity to your pump and pool size.

To answer your unasked question, once the water is clear you won't need to clean the filter daily.

 

[baudilus]

Sooo.. short of spending the big bucks on a DE filter, I should stick with cartridge?

Denis

From what I understand, and given the current state of your pool, if you were to switch to a DE filter now you would regret it for the rest of your life. If your cartridge gets that dirty within an hours, a DE filter would probably need cleaning twice as often and take twice as long to do, plus you'd be going through DE like a flesh-eating bacteria through . . . uh . . . flesh.

 

[257WbyMag]

If your filter has a single cartridge, it is probably too small for the job. At least that is what it sounds like to me. Routinely, we advise folks who are shopping for a new filter to purchase one larger than you need because the efficiency is so much better that way.

Have you been using skimmer socks?
If you have a suction side cleaner, are you using a leaf trap?
Is your strainer basket intact and does it properly seat itself in the strainer on your pump?

I can go a full six months with a heavy swimmer load, suntan oils, dust and dirt, and pollen like you wouldn't believe before I need to clean my cartridges.

 

[frustratedpoolmom]

I understand now.

I don't know if there is a more efficient way to clear it up in your particular situation - short of draining it completely and then using a scoop of some sort to shovel out the solids. Maybe someone has an idea?

I don't know if replacing the filter entirely is the way to go or not.... tho I do now understand your frustration better and can see why you have replaced the cartridges already and have to clean them so often/quicly... not much choice in that is there?

Obviously there is significant differences in our situation. I've never had a true green algae 'bloom' and I'm on my second filter replacement in after 8 full seasons, and it's still holding up quite well.

If you didn't want to drain, I suppose you could buy a sand filter, clear the sucker up, and then if you weren't satisfied with the general daily filtration results of a sand filter, you could always give the cart filter another try (with a fresh filter, of course.) Upgrading to a DE would be an expensive decision that I don't think you'd be happy with.

 

[JasonLion]

An oversized pump combined with a too small filter will cause problems regardless of the kind of filter you get. Sand filters are more difficult to destroy than cartridge filters, but you shouldn't run the system with a way oversized pump in either case. Fortunately that problem is already resolved.

Sometimes with a cartridge filter, if it needs to be cleaned constantly, and it wasn't always like that, then it needs a more through cleaning than just washing it off. Usually an overnight soak in TSP or automatic dish washer detergent (one cup for each 5 gallons of water) takes care of it, but sometimes you also need an acid soak after that. This probably doesn't apply in your situation, since it normally takes much longer before this issue comes up.

Aside from that "extra dirty" cartridge issues, constantly needing to clean the filter has little or nothing to do with the kind of filter. What matters is the size of the filter. The larger the filter, of any kind, the less often you need to clean it.

There is no one best kind of filter. Everyone has their preferences, but that doesn't mean yours will match theirs. Likewise, no one kind of filter is significantly more efficient than another. Larger filters, of any type, are more efficient.

Switching to a new filter is fairly easy. You will need to do a little plumbing. If you pick a sand filter you will also need to add sand. Switching to either sand or DE means you need to figure out where you want to run the backwash hose.

Personally I like my sand filter. But I know lots of people who are extremely happy with their cartridge filters. Just get the largest filter you can afford/fit in the available space. A 250 lb sand filter will work, but a larger one would be better.

 

[duraleigh]

Dennis,

I believe water quality is your issue....not the filter. I think you have algae. If you will post a full set of test results and tell us how you chlorinate your pool, I think you likely have inadequate chlorine in the pool and that is causing your filter to clog.

 

[frustratedpoolmom]

If you click on the link the OP posted you can see the issue the OP started with. Sounded to me like clearing it is a work in progress, but your right, I didn't even ask if he's still shocking!

 

[denisbaldwin]

If your filter has a single cartridge, it is probably too small for the job. At least that is what it sounds like to me. Routinely, we advise folks who are shopping for a new filter to purchase one larger than you need because the efficiency is so much better that way.

You may be onto something. This is the Hayward 1200 on a 12,000 gallon pool. I'm not sure if that's too small or not, especially considering it's 120 square feet of filtering power. The next one up in the Hayward line is the C17502, which does 175 square feet. Do you think it's worth upgrading? or perhaps to an even bigger filter?

Have you been using skimmer socks?

Yes. I used them in both my main skimmer and I double up one in the pump on the hair skimmer basket. That helps tremendously, especially with leaves. The only thing that gets through is the dirt and dead algae, which is what clogs up the filter so quickly.

If you have a suction side cleaner, are you using a leaf trap?

Just the manual floor vacuum. I have one of the wheeled flat ones that goes into the skimmer. It works if I take it slow, but the muck inevitably gets raked back up even if I'm VERY slow and I have to wait until it calms again. I'm not using a leaf trap, just the socks and skimmer baskets.

Is your strainer basket intact and does it properly seat itself in the strainer on your pump?

Yes and yes. I bought it brand new when we got this place and it fits snug. The one in the pump is also brand new, as I bought the pump brand new only a few weeks ago.

I can go a full six months with a heavy swimmer load, suntan oils, dust and dirt, and pollen like you wouldn't believe before I need to clean my cartridges.

My old pool was like that. Then again, it was clean when I moved in and stayed that way as long as I was on top of the chemicals.

 

[denisbaldwin]

There is no one best kind of filter. Everyone has their preferences, but that doesn't mean yours will match theirs. Likewise, no one kind of filter is significantly more efficient than another. Larger filters, of any type, are more efficient.

Jason - I've come to really appreciate your insight (along with many others on here). Let's say I do want to stick with a cartridge. What's the largest cartridge filter I can readily find at a pool store or a trusted online outlet? I don't mind making an upgrade (even if it costs me some bucks) if I feel like it will help the situation.

 

[denisbaldwin]

Dennis,

I believe water quality is your issue....not the filter. I think you have algae. If you will post a full set of test results and tell us how you chlorinate your pool, I think you likely have inadequate chlorine in the pool and that is causing your filter to clog.

Duraleigh - At first, this was definitely the problem. In the last 10 days, I've been able to shock the pool to where it holds chlorine atleast 4-5 days before dropping below 3ppm. I has my pool water checked the pool this morning after not putting chlorine in it since last Thursday and it still shows 3ppm of free chlorine. The thing about the water is that it's clear, very clear, all the way to that bottom 1/4" or so of dirt that I vacuum up every day. I get almost all of it before the water gets ruffled around and I have to let it settle again.

Here's my results:
Total Chlorine - 4PPM
Free Chlorine - 3PPM
pH - 7.4
Acid Demand - 0
Base Demand - 0
Total Alkalinity - 130PPM
Calcium Hardness - 150PPM
Stabilizer - 60PPM
Total Dissolved Solids - 900PPM

Looks like my dissolved solids are still high and I'm gonna need to put more chlorine in soon, but am I that far out of line on water quality?

 

[frustratedpoolmom]

Aha.... we are getting somewhere... :idea:

First, I don't think the filter is too small for that pool. If you want to upgrade the size, that's up to you but that size should be ok.

You have a CC of 1. This means you need to shock.

Your FC is already too low for your CYA level of 60.

If you refer to the CYA chart, you'll see your recommended levels. Your "min" level of 5, your "Target" of 7(for nitely dosing) and your "shock" level of 24. You need to raise it up to 24 and hold at at 24, until your FC holds overnight and your CC is .5 or less and this is confirmed thru the use of an FAS-DPD chlorine test, via performing the Overnight FC Loss Test. This is the only way to confirm if the organics that are present in your pool (before and still, now) are completely dead. If you do this, your filter will stop clogging so much, and you'll be on the quick road to a trouble free pool.

Ignore Total Dissolved Solids, essentially irrelevant.

Lastly, I recommend that you get your own test kit (see here), if you are relying on the pool store.

 

[257WbyMag]

If you click on the link the OP posted you can see the issue the OP started with. Sounded to me like clearing it is a work in progress, but your right, I didn't even ask if he's still shocking!

Yes, that does make sense. I didn't read close enough. It's understandable now that the cartridge could require more frequent attention. My bad.

 

[JasonLion]

What's the largest cartridge filter I can readily find at a pool store or a trusted online outlet?

The Pentair Clean and Clear Plus, and Hayward SwimClear, series both go up to over 500 square feet. The 500+ sqft models are sometimes difficult to find, but the next size down, 400+ sqft, should be reasonably easy to find.

 

[baudilus]

Up-sizing your filter would provide a benefit of less frequent maintenance, and of course more filtering area, but the added cost may not be worth it since your current filter should be enough. Maybe you should put that money towards an SWCG instead?

 

[frustratedpoolmom]

Honestly Denis, focus on completing the shock process as I outlined above, and give a clear pool a run with the existing set up before you decide whether or not to upgrade. (assuming this replacement cart is not shot as well. )

 

[denisbaldwin]

I'll keep shocking and keep monitoring the chemicals.

 

[The Mermaid Queen]

Honestly Denis, focus on completing the shock process as I outlined above, and give a clear pool a run with the existing set up before you decide whether or not to upgrade. (assuming this replacement cart is not shot as well. )

About halfway through this thread, this is what I wanted to say! Just be patient and clear your current mess as FPM outlined above. THEN see what happens!

When you have a BIG mess, a sand filter is the easiest to deal with for clearing your mess, as backwashing is pretty easy compared to hosing off a cart. BUT, when your pool is clean, a cart usually requires less frequent cleaning, sometimes only a couple times per season, depending on the size of the cart and the length of the season.

POP - Pool Owner Patience (and persistance)
Don't let your FC level be dropping for 4-5 days before boosting it back up... To properly shock, you need to KEEP your FC at shock level (in your case 24) at ALL TIMES, or at least as close to that as possible. Shocking is a process, not an event or product!

Best of luck! Follow the guidelines here, ask questions, have a little patience, and you will be well on your way to a Trouble Free Pool!!