Salt Or Chlorine

[Lonnie]

Need a little help. I have had an in-ground pool for 23 years, and ran a Chlorine system with the automatic chlorinator, with no issues. We have recently moved and are in the process of looking at in-ground pools again. We have been to a lot of different places and it seems either they are for it or against it. The ones that are against it say they cell a lot of salt system however in the long you are going to be spending about the same in the price chemicals, because of the replacement of the cells in the salt system every 3-4 years. Is this true?

I would like to hear from the people that have switch from chlorine systems to the Salt/chlorine generating system.

What are the pro's and con's for the salt system?

I know in the past I usually spend roughly $300 a pool season between Chlorine, stabilizer, Shock, Deep Blue, and algaecide?

I would also like to know if I will I still need the Shock, Deep Blue, and Algaecide chemical while running the salt system?

Not sure if this matters or not but I will be going with the same pool that I had in the past. 24' Octagon.

Sorry for so many questions, just don't want to go out and buy something, that i'm going to be unhappy with later.

Lonnie

[waterbear]

A salt system is a chlorine system, you are just making the chlorine in the pool instead of adding it. I would not go back to manual chlorination. I love them and have one on my own pool. It is not a money saver but the convenience factor is really what it's all about and it does make water maintenance easier IMHO. However, it does not eliminate the need for water testing or balancing and does have some quirks you need to learn about (but that is why we are here).

If you go with salt go with a cartridge filter over a sand or DE filter and don't install an autofill on the pool if possible. It will make maintaining chemical levels (salt, CYA, borates) a bit easier.

[kozmo]

i concur with Waterbear. I've had a salt system now for 10 years. YOu still have to by acid, stabilizer, algeacide, etc., but you will save some money on Chlorine. The two reasons I like it; I don't have to mess with Chlorine chemicals (one less caustic chemical to deal with) and we love the feel of the water. You will at some point have to replace your salt cell. I got 5 years out of my first one. We moved and built a new pool so have only had this one 3 years...still working fine.

[txpoolguy]

Long term, you probably won't realize huge savings with the ECG. Cell life varies by water quality in your area, proper maintenance, etc. Hopefully you won't need one more than 5-7 year intervals, but that's not absolute. The convenience is a huge plus, and the "feel" of the water is far superior with an electronic chlorine generator (salt system). You shouldn't need the algaecide or Deep Blue if you're maintaining other chemicals properly. The Deep Blue sounds like a clarifier commonly used with sand filters. You won't need much shock, but it's handy to have on hand for use after heavy rainfall, etc. Stabilizer or Cyanuric Acid will still be necessary, and will be kept at a higher level.

Maintaining all the "other" chemical aspects of your water is actuallly more important than manual or electronic delivery of chlorine, although the ECGs are well liked in most areas.

[waterbear]

Maintaining all the "other" chemical aspects of your water is actuallly more important than manual or electronic delivery of chlorine

Very true word!

[AFiremanFirst]

Waterbear- Why is it that someone should use a cartridge filter over DE or Sand with a salt pool? I've seen this as a common practice but don't understand it?

[Lonnie]

Waterbear- Why is it that someone should use a cartridge filter over DE or Sand with a salt pool? I've seen this as a common practice but don't understand it?

Good question. I believe one of the pool stores I have a quote from, quoted me with the sand filter.

[Lonnie]

Also while we are on this subject. What is a good Brand? One places as suggested InteliChlor by by Pentair, and 2 others have suggest against Pentair (even though they do offer them), and say to go with Hayward.

I do know from the past I have ran Hayward equipment, and have been very satisfied with the quality of product.

I do have another question. When the cells go out. Do they give warning or is it one of those things that one day, it just doesn't work in the middle of a season? Just something I want to be prepared for if that is the case.

[HouTex1962]

I have a cartridge filter for my three month old in ground pool and it originally was designed to go with a SWCG. I decided against a SWCG midway through construction, but we stayed with a cartidge filter (the plumbing was not set up for backwash to the sewer). My problem was that the CYA level went to 100 ppm in just over two months using 3" tri-chlor tabs. I drained half of the water out of the pool and now I'm using liquid chlorine at least until summer. It hasn't been too inconvenient yet, but it's not really hot yet. I will probably install a SWCG this summer. And we love our cartridge filter. It's a pentair 480. The water could not be prettier.

[waterbear]

Waterbear- Why is it that someone should use a cartridge filter over DE or Sand with a salt pool? I've seen this as a common practice but don't understand it?

It's really very basic once you think about it.

With a salt water chlorine generator you need to keep the salt and CYA levels (and borates if used) constant for best performance. With a backwashing filter (sand or DE) you dilute these chemicals with each backwash and topping off. While this is desirable when using stabilized chlorine in a feeder or floater (where constantly rising CYA is a problem and dilution is welcome) it is not desirable with a SWCG where you would need to be constantly testing and topping off the salt and CYA (and borates). Same reason I advise against an autofill. It just makes water maintenance much easier with a SWCG.

[waterbear]

Also while we are on this subject. What is a good Brand? One places as suggested InteliChlor by by Pentair, and 2 others have suggest against Pentair (even though they do offer them), and say to go with Hayward.

I do know from the past I have ran Hayward equipment, and have been very satisfied with the quality of product.

I do have another question. When the cells go out. Do they give warning or is it one of those things that one day, it just doesn't work in the middle of a season? Just something I want to be prepared for if that is the case.

the Pentair units have had some problems in the past with circuit boards but they seem to have worked them out. Hayward (Goldline) units have a proven track record (and I have one on my own pool). There are many other good SWCGs on the market, btw.

How long a cells lasts depends a lot on how you keep your water balanced and oversizing the cell is usually a good idea (for several reasons). Cells normally decline in chlorine production over time so you generally know when the cell is about to die but sometimes they just stop so there is no hard and fast rule. If the cell does die it's not the end of the world, just manually chlorinate with bleach or liquid chlorine until you get the cell replaced (after all, this is exactly what the cell is producing in your pool). You still need to be testing your water so you will know if and when the cell stops working so it's nothing to lose sleep over.

[Lonnie]

How often do you have to test, running the SWCGs? That is one thing I can say I never really did on my pool, after the first couple of years with the chlorine tablets.

I would start the pool every year the same way. Run pump 24 hours. Then once the water was clear (with in a couple days), after a week backed the pump down to 10 hours, make sure there is plenty of Chlorine in the Automatic Chlorinators, shock it weekly, backwash the filter, and every 2 weeks add algaecides, and clarifiers. The only time I would have to adjust differently was after a heavy rainy week, lot of swimmer, or a big temp swing cold or hot. I didnt even own a vacuum the last couple of years, because my pump would cause a nice sized whirlpool, all we had to do was jump in stir the bottom, get out let the whirlpool run for a little bit and it was all clean again. I have found the more we swam the cleaner the pool stayed.

Probably they lazy way of doing it but really never had any issues, the worst thing that would happen is the chlorinator would run out of chlorine, the water would look a little off. Then I would fill the Chlorinator up and by morning everything look great again.

[Lonnie]

Waterbear- Why is it that someone should use a cartridge filter over DE or Sand with a salt pool? I've seen this as a common practice but don't understand it?

It's really very basic once you think about it.

With a salt water chlorine generator you need to keep the salt and CYA levels (and borates if used) constant for best performance. With a backwashing filter (sand or DE) you dilute these chemicals with each backwash and topping off. While this is desirable when using stabilized chlorine in a feeder or floater (where constantly rising CYA is a problem and dilution is welcome) it is not desirable with a SWCG where you would need to be constantly testing and topping off the salt and CYA (and borates). Same reason I advise against an autofill. It just makes water maintenance much easier with a SWCG.

That does Makes since. How often do you have to change/replace the cartridge?

[waterbear]

That does Makes since. How often do you have to change/replace the cartridge?

with proper care they should last about 5 years but the do require periodic cleaning, depending on the size of your pool and filter (usually about once a month or longer between cleanings if the filter is properly sized for your pool).

[Lonnie]

Thanks!

[AFiremanFirst]

I agree that it makes sense, but the rule of thumb that seems to be common in my area is to clean cartridge filters every 4 months and DE every 6 months with monthly backwashing. I had a cartridge filter, and after installing a flow meter, quickly realized that every 3 months wasn't adequate. I then switched to a DE filter. My thoughts are this. Backwashing a DE filter once a month, with a cycle of backwash 45 secs, filter 15, times 3 equals a back wash of 2 mins and 15 secs, at 50 gpm I'm at 110 roughly gpm per month. I guess what my point is, in relation to a 16,000 gallon pool, we're talking about a drop in the bucket in chemicals. I likely lose more than that in splash out, but I still let my kids splash in the pool. And I'm leaving out that the water I lost cleaning my cartridge filter monthly closes my gap. IMHO. I'd much rather have a DE filter. It's more effecient. The ability or inability to backwash to me is priceless, and testing chemicals is not that difficult, you should be doing this anyway. If you're not testing your pH in a SWG pool weekly, then what are you doing?

Again. I have a flow meter. Few seem to be using flow meters, but after seeing the results from a cartridge to a DE, I have just concluded that DE is the way to go.

Waterbear, I do appreciate your explanation. It does make sense, I'm just not a big fan of cartridge filters, they are easier to clean, thank God, since mine needed to be cleaned monthly. I'll stick to adding my chemicals!

[waterbear]

I agree that it makes sense, but the rule of thumb that seems to be common in my area is to clean cartridge filters every 4 months and DE every 6 months with monthly backwashing. I had a cartridge filter, and after installing a flow meter, quickly realized that every 3 months wasn't adequate. I then switched to a DE filter. My thoughts are this. Backwashing a DE filter once a month, with a cycle of backwash 45 secs, filter 15, times 3 equals a back wash of 2 mins and 15 secs, at 50 gpm I'm at 110 roughly gpm per month. I guess what my point is, in relation to a 16,000 gallon pool, we're talking about a drop in the bucket in chemicals. I likely lose more than that in splash out, but I still let my kids splash in the pool. And I'm leaving out that the water I lost cleaning my cartridge filter monthly closes my gap. IMHO. I'd much rather have a DE filter. It's more effecient. The ability or inability to backwash to me is priceless, and testing chemicals is not that difficult, you should be doing this anyway. If you're not testing your pH in a SWG pool weekly, then what are you doing?

Again. I have a flow meter. Few seem to be using flow meters, but after seeing the results from a cartridge to a DE, I have just concluded that DE is the way to go.

Waterbear, I do appreciate your explanation. It does make sense, I'm just not a big fan of cartridge filters, they are easier to clean, thank God, since mine needed to be cleaned monthly. I'll stick to adding my chemicals!

Then again, let's look at DE for a minute. When you backwash you don't know exactly how much DE you are removing so you really don't know how much you need to add so you run the risk of under or overcharging. Undercharging can lead to fouled grids which means breaking down the filter and soaking the grids. Over charging can lead to bridging which means breaking down the filter and chipping out the cement like hardened DE between the grids (NOT a fun job).

IMHO, DE filter really need to be broken down and cleaned and NOT backwashed. The only time backwashing is useful is when clearing a green pool and the filter is clogging fast with the dead algae and once the pool is cleared the filter should be broken down and cleaned. Your flow meter does not tell you if your filter is properly charged so it's a nice adjunct to how often to clean but I do not think it is really more useful than a pressure gauge. Also consider that a dirty Cart will filter better than a clean cart and slower flow rates filter better than faster ones. Lots of overlooked factors here.

As far as cart cleaning goes, only rule of thumb I am aware of is when there is a 6-8 psi rise in pressure! Often that meant about once a month but with the trend to oversize carts that time frame is becoming longer. With my setup that is about a year but I do clean mine 3-4 times a year. I don't think a cart should really go more than aobut 4 months between cleanings.

Flow meter would not do me a lot of good since I run my two speed pump on low most of the time so what are flow rates going to tell me (short of when they stop altogether?)

The reason I have a SWCG is that I do not want to be adjusting chems all the time. My salt, CYA, and borates stay stable and I do not have to make adjustments more than about every 6 months. Even my pH stays pretty stable, thanks to a combination of low TA fill water, low TA in the pool, 50 ppm borates, CYA at 80 ppm, and salt cell oversized for the pool size so on time is low. Testing is not the issue. It's dragging out and measuring the salt, CYA and borax and acid that I don't want to do all the time!

[AFiremanFirst]

With only a few years of experience and a handful of pools (20 give or take 3 seasonally) it seems I'm unfamiliar with "cement" like hardened DE? I will concure that how much or how little DE to add can be argued, as it seems a highly debated subject matter. I fell in love with my flow meter when I realized that a 3 psi increase in my cartridge filter equated to a 50% reduction in flow. I've heard the arguement about psi and flow, but at the end of the day, if you don't know your flow, how do you know how long it takes to turn over your pool, I realize this is a debated item as well.

slower flow rates filter better than faster ones? In comparing sand to cartridge to de, I'd a gree. But you get better flow rates from a de 60 than a de 48, because there is more surface area primarily, but flow rates are dictated by many factors such as head, pump, etc and filter flow rate is only as good as the pump and head pressure will allow.

I never ran my cart to a 6-8 psi increase, well because if at 3 psi I lost 50% of my flow, who knows what my flow rate would be at 6-8 psi, but since energy conservation seems to be the new black, I'd rather not run my pump any longer than necessary.

You have raised my curiousity about your chemicals. My first thought is that borates are poisinous to dogs? Is this true? It's just something I have read so I've stayed away from them, any education you can offer about borates would be greatly appreciated! I also understand that your swcg is oversized and that your run time is less than if it were the "recommended" size, but when it runs, does it do more/less than turn salt into chlorine. In my area, pH is a constant adjustment, especially in salt water pools!!! Everything I have read suggest that it should be, so contradicting my experience and what I have read, I'm intrigued that you don't make many adjustments. My pH goal is 7.4-7.6 since the human eye has a pH of 7.5 do you keep your pool at something different? If so why? TA! Ta is a buffer for pH preventing excessive peaks and valleys from "forgein" pH introduction, right? And isn't the ideal range 80-100? I'll add that your cya affects your TA reading as do other minerals in the water. I'm a big fan of the saturation index, and I try to keep my si between 0.3/-0.3, to do this water temp, pH, calcium hardness, and TA all play a big role, and yes they all must be near the "suggested" range.

I too have a swcg!!! And as a tech, I suggest the customer either be intimately familiar with pool chemistry or have a tech that will at minimum help them balance their water on a regular basis. Tabs IMHO are nearly idiot proof. Yes, they add too much calcium, and CYA, but they are acidic, and provide chlorine easily. Seldom do I have a new customer with a tablet pool that looks like a lagoon, but poorly managed salt pools can get away from a homeowner in a hurry. Couple a cart filter with it, and now my work has become more costly!

I respect your knowledge and input, you have consistently taught me many things and as I fine tune my knowledge base, I look forward to your reply. It's funny to me how each pool has it's very own personality, and how as pool guys we each have our own on how to maintain each one, the combinations are infinite. Thanks again for anything you can teach me!

[chem geek]

As for borate safety, see this post. Basically, unless your dog is drinking substantial amounts of water from the pool every day, they are not a problem. Roughly speaking, a 20 pound dog drinking around 2 quarts of 50 ppm Borate water every day would be at the No Observed Adverse Effect Limit (NOAEL). The main adverse effect was seen at 3 times that amount (so equivalent to 6 quarts of 50 ppm Borates every day) where male dogs had reduced testicle size. This is why I recommend not using borates if you've got a dog that regularly drinks from the pool -- just to be on the safe side, but this is a conservative recommendation.

As for pH rise, Total Alkalinity (TA) is NOT just a pH buffer, but a SOURCE of rising pH in its own right since most of TA represents the degree of over-carbonation in the pool. This over-carbonation results in carbon dioxide outgassing from the pool which causes the pH to rise. A TA of 80 ppm is NOT necessarily appropriate. A lower TA is often better for pools using hypochlorite sources of chlorine including saltwater chlorine generator (SWG) pools. This table shows how over-carbonated a pool actually is at various TA and pH levels (the color coding is somewhat arbitrary since actual outgassing rates depend on the amount of aeration and the square of the TA, not mostly linear as shown in the table; SWG pools may need to get to a number of around 3.5 or lower in the table to get to decent pH stability).

As for a pH target, 7.7 or 7.8 is not a problem for eyes. Yes, 7.5 is an average pH for tears, but the pH has to be pretty far out of line to get eye irritation (see this post for more details). A pH from 7 to 9 did not show differences in eye irritation. The salt level was more of a factor (higher salt level is less irritating probably due to less osmotic pressure) and chloramines were irritating.

If you've taken the CPO course, then you might find Certified Pool Operator (CPO) training -- What is not taught useful.

[waterbear]

chem geek beat me to the punch. The only thing I will add is that the less a salt cell is on the less production of hydrogen bubbles and the less outgassing of CO2 and therefore less pH rise, hence oversizing the cell since it equals a shorter run time. Ditto for keeping the CYA at max with a SWCG. As far as borates, I have three dogs. I just trained them that the pool is NOT a large water bowl and always have fresh water for them (and my cat) by the pool and spa since we all spend a lot of time outside in the water.

As far as DE goes, too much DE will bridge the grids and DE can also clog plumbing if not made into a proper slurry. It literally hardens into a rock like substance. In a pipe it can become a permanent clog that necessitates replacing the pipe. Work with enough DE and DE filters and you will become more familiar with it than you ever wanted to!

[AFiremanFirst]

Thank you both!