Soft or not?

[rinaldok]

Folks, I need your help please.

In a couple days my pool will be getting drained to start the resurfacing. It will be mini pebble. Great timing, since we just broke a heat record and are on the books for 100+ through the week and high 90's - 100's ongoing after that until the "real" heat sets in. Oh well.

Recently I discovered that my auto fill (and hose bibb) were plumbed through the house water softener.

I was told by PB that I should NOT run softened water to the pool, and that likely contributed to the eventual demise of the plaster due to calcium leeching. However, my calcium is at like... 1200... so, for at least the 2 years that I've owned this pool there hasn't been an issue with calcium deficiency. I also noted that my salt is at 4600 or possibly higher, I stopped the test, and I don't run a salt pool (yet). So, that salt has been building up from the softened water for a long time.

The topic has been covered (and I just saw JoyfulNoise's post about INSTALLING a softener for his pool fill), but like most things there are opinions and arguments on both sides.

My PLAN was to convert the auto fill and hose bibb to non-softened water. My raw water tests at about 275ish ppm, however I find this odd... the 2015 water quality report for my area lists 32ppm calcium. The 2016 water quality report does not have a number for calcium.

Now for the twist -- my plumber (who I trust as a plumber, not as a pool chemistry guru obviously) is big on the NuvoH2O system. It's a saltless softener, no tanks. He wants to change out my softener for this new system as part of my work.

The NuvoH2O works by using citric acid to surround (chelate) the minerals (such as calcium) so that they cannot bond to plumbing or fixtures, rather than removing the minerals like a salt softener.

Please note this part as it's of particular concern to me:

*The claim by the MFR and by my plumber are that not only does the the NuvoH2O softener prevent new scale buildup, but they claim that the citric acid will break down existing scale in plumbing, appliances, fixtures, etc., over time. That makes me wonder if it would be bad to have this water in the pool, would it attack the pool surface?

This sounds like a good idea for the house plumbing, fixtures, appliances, and water experience, but house water and pool water are 2 different animals. I was JUST about to hand him the $3000 for the total plumbing conversion which was the NuvoH2O for the house water, and converting the auto fill to NON softened water, however now I'm not sure the best approach.

Please help!

1. Keep the auto fill line softened or not? It obviously drives the salt level up, and I will be installing a SWCG, so I'd like to keep the salt stable, but I think keeping CSI in check (slightly negative) with lower CH is more important.

2. *IF* I should keep the auto fill on the softener, is switching to the NuvoH20 a bad idea for the pool? As the Nuvo uses citric acid, is this water safe/appropriate for use in the pool? Will the citric acid cause any negative effects? Or would it perhaps help keep pH from rising? Also, since the calcium is not removed, it is simply surrounded by the citric acid... would the citric acid at some point potentially "let go" of the calcium and then it would drive up my CH anyway? I'm not a chemist, so please help me out here.

Thanks!!

 

[MinerJason]

I'm not in any way qualified to answer your questions, but I think I can shed light on a couple of things. The water hardness here in southern AZ varies greatly seasonally, and there's a ton of variation between source wells. This means that the water in the next door neighborhood could be drastically different from yours, and that your own water will have drastic changes throughout the year, so taking an annual average calcium value from a water report for a whole water district isn't going to tell you much. Also, if you look closely at the water report you'll notice three asterisks next to the calcium level, which if you look further down indicates that it was from a single sample.

The 1200 ppm calcium seems really high to me, how are you testing that, and how sure are you of the accuracy?

Have you tested the water after it's run through your water softener?

As far as the Nuvo H2O system, I don't think I'd use that for my pool. Adding citric acid and lowering the pH of your pool water seems like a sure fire recipe for deterioration of the plaster. Just my opinion though, hopefully someone who knows more about it will chime in.

 

[JamesW]

Citric acid is not good for the pool. Chlorine will quickly react with it and they will neutralize each other.

The reaction can also produce chloroform, which is not good.

 

[proavia]

CH never leaves the pool with evaporation. And chances are pretty much the entire pool volume will evaporate over the course of a year. So each year you are adding about 275 to your CH reading. In around 4 years time, the CH could easily be over 1200.

With our high CH water in the valley, it would be best to do the initial fill with non-softened water. Your non- softened water is probably in the 250-300 range for CH. Pool School recommends the level be 250-350 for a non-SWG pool and 350-450 for a SWG pool. So you would adjust your CH level after the fill for your pool type. Then use softened water - from a normal salt based water softener - for your make-up water (auto fill). This would help keep your CH within range.

A properly operating water softener shouldn't be adding salt to the water. However, ALL forms of chlorine - liquid and solid - add a little salt to the water. And like CH, salt doesn't leave the pool through evaporation.

As for the new fangled softener that uses citric acid - not for pool water.

 

[rinaldok]

Thanks for the feedback so far guys.

The reaction can also produce chloroform, which is not good.

Well that would certainly be.... not...............ideal.

The NuvoH20 *seems* like it would be a good system for the house water... however it's not much of a win if I end up needing to keep a salt softener around just for pool water, I might as well just continue to use the regular salt softener for the house water as well.

One thing is for sure: No NuvoH20 water in the pool.

The $64,000 question now is:

1. Run salt-softened water to the pool to keep CH in check, and deal with rising salt levels over time (periodic drain/refills?)

2. Run hard water to the pool to keep salt constant(ish), and deal with rising CH levels over time (periodic drain/refills?)

Since I see more people here talking about installing softeners for the pool than taking them out, it would seem to me that the answer is #1.

Agree/disagree?

If #1, then I have to decide if I just stick with salt-softening for the whole house (sane/logical choice) or run a dual-softening setup with Nuvo for the house and put the salt softener dedicated for the pool line.

 

[duraleigh]

I am not making the connection of salt and a water softener. Do you think the softener is adding salt to your pool?

 

[rinaldok]

CH never leaves the pool with evaporation. And chances are pretty much the entire pool volume will evaporate over the course of a year. So each year you are adding about 275 to your CH reading. In around 4 years time, the CH could easily be over 1200.

Exactly, and I have no idea how long it's been since this pool was last drained. I've lived here for just shy of 2 years.

With our high CH water in the valley, it would be best to do the initial fill with non-softened water. Your non- softened water is probably in the 250-300 range for CH. Pool School recommends the level be 250-350 for a non-SWG pool and 350-450 for a SWG pool.

Right, and that was the plan for the short term. As I mentioned my water tested at around 275ish. I don't much like the CH test, I'm not at all colorblind but I sometimes have difficulty distinguishing "blue" from "purple" on that test. I did the test 3 times to be sure and I was right in the range of 275 each time so I think I was seeing it correctly.

A properly operating water softener shouldn't be adding salt to the water. However, ALL forms of chlorine - liquid and solid - add a little salt to the water. And like CH, salt doesn't leave the pool through evaporation.

Actually, that's not quite true. Softeners are ion exchange systems, they take calcium/magnesium hardness out by exchanging it for sodium ions. It doesn't add a LOT of salt to the water, but it does add some. At 20 gpg hardness, approximately 60mg/gal of sodium is added to the water. And yes, it just continues to accumulate. That, plus the natural salt resulting from chlorine, does contribute to rise over time, but I really can't fathom how I got up to 4600 or higher unless someone added a whole bunch of salt at some point in the past, maybe planning for a SWCG, but never got around to installing it. 4600 seems like a LOT of salt for a non-SWCG pool.

 

[borjis]

I really can't fathom how I got up to 4600 or higher unless someone added a whole bunch of salt at some point in the past, maybe planning for a SWCG, but never got around to installing it. 4600 seems like a LOT of salt for a non-SWCG pool.

Good point.

I do know some people add enough salt to make an SWG function, but don't actually have an SWG.
Something about it "feeling amazing", compared with no salt added.

My sister in law (a fan of saltwater) asked me if I was planning on that and I said no.

 

[proavia]

Actually, that's not quite true. Softeners are ion exchange systems, they take calcium/magnesium hardness out by exchanging it for sodium ions. It doesn't add a LOT of salt to the water, but it does add some. At 20 gpg hardness, approximately 60mg/gal of sodium is added to the water. And yes, it just continues to accumulate. That, plus the natural salt resulting from chlorine, does contribute to rise over time, but I really can't fathom how I got up to 4600 or higher unless someone added a whole bunch of salt at some point in the past, maybe planning for a SWCG, but never got around to installing it. 4600 seems like a LOT of salt for a non-SWCG pool.

I'm pretty sure that sodium bicarbonate (baking soda?), which is different from sodium chloride (table salt), is formed through the water softening process. Yes, there is additional sodium in softened water, but not salt.

 

[Dirk]

I have explored these issues ad nauseam on this site, within various threads of mine. The water softener is NOT adding the salt to your pool (not in any meaningful way, anyway). I got schooled for worrying about that by a TFP expert that would know. The fill water, chlorine, acid, other chem's and PEOPLE are responsible for the salt build up, NOT the softener.

You've already figured out not to go with the lemon water in the pool!

Why complicate?

Fill your pool with street water. Adjust to get CH to minimum level. Let it rise slowly with what gets past your softener (if any).

Auto-fill it with soft water. Run the same soft water in your house.

Take a nice trip somewhere with the money you just saved!

I replumbed my auto fill to both softener and street (I can add either now), and did so I can control CH up if need be, or keep it perfectly level. So far so good.

What your PB was warning was half-true: you wouldn't fill a pool with soft water (even if you happened to have a magical softener that could do so), because plaster pools need CH. But topping a pool with CH-free water, when the water already has a proper amount of CH, is just fine.

You'll still have to test CH, and maybe adjust once in a while, because you can lose CH from splash out. It's not normally noticed by the average pool owner because so much CH is always coming in. I actually lost some CH since I switched to soft water, so I have to add some! Cool, right? But I don't have to buy any, I just switch over to "street water" for a bit.

You will still have to drain your pool someday (partial, maybe), because of the salt build up (that's unavoidable, with or without SWG), but it won't be necessary because of CH-rise, and probably not as frequent for that reason.

If you want to give your plumber some money, have him replumb that hose bib off the softener. You shouldn't be watering your garden with that. Put in a proper back-flow preventer for the auto-fill, and connect that to both soft and hard water.

Done.

Here's what I learned and how I did it:

Water softener connected to auto fill, and new plaster start up.

 

[rinaldok]

Why complicate?

Tis my nature. When I get into something I overanalyze and fixate on "ultimate" solutions.

Fill your pool with street water. Adjust to get CH to minimum level. Let it rise slowly with what gets past your softener (if any).

Auto-fill it with soft water. Run the same soft water in your house.

Take a nice trip somewhere with the money you just saved!

Yeah, this is the most logical and pragmatic solution.

I have backed off the ledge a bit, I had gotten a lot of bad information thrown at me from people who are supposed to know better, and it made me second guess.

I replumbed my auto fill to both softener and street (I can add either now), and did so I can control CH up if need be, or keep it perfectly level. So far so good.

This is probably what I will do as well at some point.

I was seduced by the claimed merits of the Nuvo system... no more tanks, reclaiming some floor space in the garage, no more salt to buy, and it can reverse scale over time in the household appliances/pipes/etc.

If I went with the Nuvo for the house, the pool would get city water and I would likely be perpetually battling high/rising CH. If I want better water for the pool, I have to keep a salt softener around, and it really doesn't make much sense to run 2 different softening systems. At the end of the day, it looks like the clear choice is to keep on truckin' with my existing softener setup, and leave the line plumbed as it is, possibly adding a second non-softened line as you did with a valve to switch.

 

[Dirk]

If I went with the Nuvo for the house, the pool would get city water and I would likely be perpetually battling high/rising CH. If I want better water for the pool, I have to keep a salt softener around, and it really doesn't make much sense to run 2 different softening systems. At the end of the day, it looks like the clear choice is to keep on truckin' with my existing softener setup, and leave the line plumbed as it is, possibly adding a second non-softened line as you did with a valve to switch.

Not knowing anything about Nuvo, it's sounds a little like a solution looking for a problem. I know there are some snake-oil hard water solutions floating around that don't work (magnets or electro-fields are something). I think you've got your answer: some tried and true tech that you already own. You'll be happy with the setup... Check out my thread for what I think is the best way to connect two water sources to a pool.

When my salt gets to be too high, I'm going to fool around with water density and try to float fresh water on top of salt, while sucking salt water out from underneath, to bring down salinity without exposing the plaster surface, or take any weight off of it (two things not so great for plaster, especially aging plaster). We'll see. Hopefully that'll be many years from now...