A few spa water questions after reading Stickied and other threads

[DownEastSpa]

Hello all!  Long time reader first time poster, as they say.

I've read the many great sticky threads on Ta, dichlor/bleach, etc etc over the past several weeks on here trying to educate myself.

I still have a few questions.

I have a new in November 2021 350 gallon spa, with the Freshwater Salt system.

No major issues, but I want to stay ahead of anything that could damage tub, and be knowledgeable enough to correct issues as they pop up.

First question - how does TA affect foaming?  I know low pH can create foaming, but does a lower TA do the same?  I have a bit of foam, but nothing I'm worried about; trying to learn, that's all.

Second question - do I need to bump my FC to 5ppm once a month or so in my Freshwater Salt system?  So far no issues maintaining 3ppm FC per the Freshwater manual.  I bumped new fill water to 5ppm to sanitize initial fill per instruction manual on Freshwater system.  The printed manual that came with the Freshwater system says yes do it as part of monthly maintenance (bump FC to 5ppm, clean filters).  However the newest Freshwater PDF manual online does not say anything about a monthly bump to 5ppm FC, and my dealer said as long as system is maintaining 3ppm recommended FC you do not need to do that.

Third question - I have a Taylor 2006 and have been geeking out with it for the past week or so that I've had it.  I used the forums' sticky'd acid/aerate method over the past few days to get my TA down and PH to where it needs to be.  I've used the recommendations I've seen on here from @waterbearand @chem geek for a low TA and pH around 7.6-7.8, and I've used the Freshwater Salt System instructions for CH and FC.  question below under water info

My current water info - 

Filled through well-water softener, and Watkins Clean Screen hose-end filter.  Water is 3 months old, from brand new fill/brand new hot tub in early Nov 2021

Taylor 2006 tested

water temp - 100F

FC - 3.8

Salt - 1700ppm (measured with Aquachek strips.  I have a Taylor 1766 kit coming Monday as well as a digital salinity tester to verify.  However the gauge on my salt system on hot tub is right in the middle of the green)

CH-50

TA-60

CYA -60 (high I know, but I'm in Maine so I can't do a half-drain and fill until it's not -10F every dang night.  I did use Dichlor only for the initial FC bumps and to get it up and running until Freshwater system could maintain 3ppm on its own)

pH - 7.6 (note this was 7.8 yesterday, but my TA was at 75-80 so I did my last 1/2 step in getting the TA down to 60, which brought my pH down to 7.6 24 hours later.  I bumped up the aerators on my jets a touch so that the auto clean (turned on) will hopefully bump pH back to 7.8

My question - the Calculator Wheel that came with my Taylor 2006 kit shows my saturation index at somewhere between -.6 and -.7  which it says will be corrosive.  Is this an issue?  I'm well within the Freshwater Salt system limits (only big difference is they recommend TA-80 and pH 7.4).

Last question - When I read the pH on the Taylor 2006 kit, I know I should do it in natural light and not in direct sun.  However, should I do it with a white background?  That seems to give me the easiest way to match the colors (holding sample at arms length against white corner trim of house, or with the yard-full of snow I currently have.  Is that the right way to do it?

Thanks so much in advance!

[dashmer]

18 hours ago, DownEastSpa said:

First question - how does TA affect foaming?  I know low pH can create foaming, but does a lower TA do the same?  I have a bit of foam, but nothing I'm worried about; trying to learn, that's all.

Not that I know of, at least not when it is in a "normal" range (60-140).  It is much more likely to have come from swimsuits or products someone has on their body (deodorant, lotions, sunscreen, etc.)

 

18 hours ago, DownEastSpa said:

Second question - do I need to bump my FC to 5ppm once a month or so in my Freshwater Salt system? 

Not sure what benefit a bump to 5ppm produces, other than to elevate it a bit before a dip or heavier bather load. 3-5 ppm is the recommended range for safety.  A bump above 10ppm, will shock your water, oxidizing contaminants, including chloramines.  This is typically recommended once per week. I am not familiar with salt systems, but I would expect you could elevate your Cl with bleach if you dont want to increase CYA levels.  High CYA level requires higher ppms for both safety and shocking.

You CH seems low, but maybe that is recommended for salt water systems.  For regular chlorine tubs, a level closer to 150 is recommended.

18 hours ago, DownEastSpa said:

My question - the Calculator Wheel that came with my Taylor 2006 kit shows my saturation index at somewhere between -.6 and -.7  which it says will be corrosive.  Is this an issue?  I'm well within the Freshwater Salt system limits (only big difference is they recommend TA-80 and pH 7.4).

I have asked about the CSI before and have been told by @waterbear that this is not a concern for fiberglass hot tubs, only for plaster.  He did say that a high CSI could lead to scaling.

 

18 hours ago, DownEastSpa said:

Last question - When I read the pH on the Taylor 2006 kit, I know I should do it in natural light and not in direct sun.  However, should I do it with a white background?  That seems to give me the easiest way to match the colors (holding sample at arms length against white corner trim of house, or with the yard-full of snow I currently have.  Is that the right way to do it?

That is how I do it.  

[waterbear]

On 2/3/2022 at 5:49 PM, DownEastSpa said:

how does TA affect foaming?  I know low pH can create foaming, but does a lower TA do the same?  I have a bit of foam, but nothing I'm worried about; trying to learn, that's all.

TA and pH have no effect on foaming. CH does. Saponaceous matter in the water (organics from bathers, creams and lotions on bathers, detergent residue in swim suits) is more likely to foam in soft water than in hard water. This is why a CH of no lower than around 130 to 150 ppm is recommended.

On 2/3/2022 at 5:49 PM, DownEastSpa said:

do I need to bump my FC to 5ppm once a month or so in my Freshwater Salt system

If you have no CYA in your water a "bump" to 5 ppm is essentially shocking the system.  If you have CYA in the water then you would want to shock to the proper level for your CYA level. My rule of thmb for when to shock is when you have persistent  CC greater than .5 ppm. The low CH could lead to foaming but they recommend that so you don't get calcium deposits on the cell electrodes.

With your CYA at 60 ppm you need to be running your FC at a minumum of 5 ppm. I would shoot for 7 to 9 ppm (and a shock level of about 20 ppm) until you can lower your CYA.

 

On 2/3/2022 at 5:49 PM, DownEastSpa said:

the Calculator Wheel that came with my Taylor 2006 kit shows my saturation index at somewhere between -.6 and -.7  which it says will be corrosive.  Is this an issue?  I'm well within the Freshwater Salt system limits (only big difference is they recommend TA-80 and pH 7.4).

Don't use it. It's for plaster surface pools and spas, not acrylic spas. Your water would be slightly 'corrosive' to plaster but with a salt system it will prevent calcium from depositing on your cell electrodes.

 

On 2/3/2022 at 5:49 PM, DownEastSpa said:

When I read the pH on the Taylor 2006 kit, I know I should do it in natural light and not in direct sun.  However, should I do it with a white background?

If outdoor stand in deep shade if possible and hold the comparator to the northern sky. CYA test should also be done in deep shade. If indoors try to test under daylight or cool white led or fluorescent lighting if possible. However, even under incandescent light the pH colors are distinctive enough to be able to tell them apart so don't lose too much sleep over this.

 

On 2/3/2022 at 5:49 PM, DownEastSpa said:

Salt - 1700ppm (measured with Aquachek strips.  I have a Taylor 1766 kit coming Monday as well as a digital salinity tester to verify.  However the gauge on my salt system on hot tub is right in the middle of the green)

Go by the gauge. The salt titrators strips are much easier to use and uses a similar silver nitrate chemistry as the Taylor chromate/silver nitrate titration test. I put less trust in salt meters (conductivity meters) unless you keep them calibrated against a standard solution on a regular basis and maintain/replace the electrode as needed. Most inexpensive ones are useless, IMHO. My goto are the built in meters/scales in the SWCG unit and the salt titrator test strips such as the ones from AquaChek and Hach.

[DownEastSpa]

On 2/11/2022 at 1:27 AM, waterbear said:

TA and pH have no effect on foaming. CH does. Saponaceous matter in the water (organics from bathers, creams and lotions on bathers, detergent residue in swim suits) is more likely to foam in soft water than in hard water. This is why a CH of no lower than around 130 to 150 ppm is recommended.

If you have no CYA in your water a "bump" to 5 ppm is essentially shocking the system.  If you have CYA in the water then you would want to shock to the proper level for your CYA level. My rule of thmb for when to shock is when you have persistent  CC greater than .5 ppm. The low CH could lead to foaming but they recommend that so you don't get calcium deposits on the cell electrodes.

With your CYA at 60 ppm you need to be running your FC at a minumum of 5 ppm. I would shoot for 7 to 9 ppm (and a shock level of about 20 ppm) until you can lower your CYA.

 

Don't use it. It's for plaster surface pools and spas, not acrylic spas. Your water would be slightly 'corrosive' to plaster but with a salt system it will prevent calcium from depositing on your cell electrodes.

 

If outdoor stand in deep shade if possible and hold the comparator to the northern sky. CYA test should also be done in deep shade. If indoors try to test under daylight or cool white led or fluorescent lighting if possible. However, even under incandescent light the pH colors are distinctive enough to be able to tell them apart so don't lose too much sleep over this.

 

Go by the gauge. The salt titrators strips are much easier to use and uses a similar silver nitrate chemistry as the Taylor chromate/silver nitrate titration test. I put less trust in salt meters (conductivity meters) unless you keep them calibrated against a standard solution on a regular basis and maintain/replace the electrode as needed. Most inexpensive ones are useless, IMHO. My goto are the built in meters/scales in the SWCG unit and the salt titrator test strips such as the ones from AquaChek and Hach.

@waterbear thanks so much for the help and the answers.

As for the salt, the Taylor 1766 said 2000ppm, the Aquachek said 1700ppm, and the digital salt meter (temp correcting and calibrated to 3000ppm)  read 2200ppm.  I dumped and fresh-water replaced ~60 gallons (350 gallon spa) to get that in line and also to help a bit on the CYA until weather warms up.

Last question - I'm getting a light white hazy line forming for 1-2" above my water line on the acrylic shell of the hot tub.  Comes off every 2 weeks or so with a rag wet with hot tub water and a light scrubbing.  I do not have a picture now, but from what I'm reading online this is most likely calcium scale?  current PH is 7.8, TH 60 and CH is 50.  Could this still be causing that slight white line?  Should I get the TA down in the 50 range and try and keep my ph down closer to 7.4-7.6?  I don't really care about having to wipe the white line every week or two; my larger concern is internal scaling on heater, pump etc.  When I replaced my last salt cartridge there did NOT seem to be any scaling on it.

 

Thanks again for the previous answers and the help!

[waterbear]

21 hours ago, DownEastSpa said:

As for the salt, the Taylor 1766 said 2000ppm, the Aquachek said 1700ppm, and the digital salt meter (temp correcting and calibrated to 3000ppm)  read 2200ppm

The Taylor test has a precision of +/- 200 ppm so the salt could bed as low as  1800 ppm or as high as 2200 ppm if you did the test correctly (stopping at a light salmon color and not going to a brick red color). IF I remember correctly the salt strips have a precision of 800 ppm and most salt meters have a precision of 100 or 200 ppm. Also, the strips and drop titration test are measuring chloride ions in the water while the meter is measuring conductivity so there are going to be differences. Your three testing methods basically gave you the same results when you take their precision into consideration.  Personally, I would pick one method and stick to it and if the salt meter on your salt system is in the proper range using whatever method you pick then don't lose any more sleep over it. I tend to lean toward a chemical test for chloride and the strips are much easier and have enough precision to get you in the proper ballpark with the least effort. My second choice would be the Taylor kit but it does take a bit of practice to get it right.

21 hours ago, DownEastSpa said:

I'm getting a light white hazy line forming for 1-2" above my water line on the acrylic shell of the hot tub.  Comes off every 2 weeks or so with a rag wet with hot tub water and a light scrubbing. 

Most likely a scum line. Scale will feel rough like sandpaper and won't come off by scrubbing. You need to use acid to get it off and your water is not going to deposit scale with the numbers you have.

I want to remind you that your spa is something to enjoy, not something to stress over and it's not a chemistry set. If your pH is fairly stable, your santizer is within range, and your water is not foaming then enjoy the water! Just remember that the salt cell is aerating your water because of the hydrogen bubbles produced in the cell so any salt system will have a higher tendency toward pH rise, which is why keeping the TA in the 50 to 70 range, keeping the pH above 7.6 and waiting until it goes above 7.8 to lower it to 7.6, and possibly adding 50 ppm borate will help combat the problem. These are just guides to find the 'sweet spot' for your water. YMMV.

[DownEastSpa]

1 hour ago, waterbear said:

The Taylor test has a precision of +/- 200 ppm so the salt could bed as low as  1800 ppm or as high as 2200 ppm if you did the test correctly (stopping at a light salmon color and not going to a brick red color). IF I remember correctly the salt strips have a precision of 800 ppm and most salt meters have a precision of 100 or 200 ppm. Also, the strips and drop titration test are measuring chloride ions in the water while the meter is measuring conductivity so there are going to be differences. Your three testing methods basically gave you the same results when you take their precision into consideration.  Personally, I would pick one method and stick to it and if the salt meter on your salt system is in the proper range using whatever method you pick then don't lose any more sleep over it. I tend to lean toward a chemical test for chloride and the strips are much easier and have enough precision to get you in the proper ballpark with the least effort. My second choice would be the Taylor kit but it does take a bit of practice to get it right.

Most likely a scum line. Scale will feel rough like sandpaper and won't come off by scrubbing. You need to use acid to get it off and your water is not going to deposit scale with the numbers you have.

I want to remind you that your spa is something to enjoy, not something to stress over and it's not a chemistry set. If your pH is fairly stable, your santizer is within range, and your water is not foaming then enjoy the water! Just remember that the salt cell is aerating your water because of the hydrogen bubbles produced in the cell so any salt system will have a higher tendency toward pH rise, which is why keeping the TA in the 50 to 70 range, keeping the pH above 7.6 and waiting until it goes above 7.8 to lower it to 7.6, and possibly adding 50 ppm borate will help combat the problem. These are just guides to find the 'sweet spot' for your water. YMMV.

Thanks so much for the answers and reassuring info.

As for the suspected scum line, my plan is to continue wiping as needed, and provided it does not get worse, simply use an ahhsome or some such spa cleaner when the weather warms up enough for a drain/fill in a couple of months.  I assume that makes sense?

I'm not really stressed about the hot tub and chemistry per se; I just am the type to try and read up as much as I can on an item or subject, so I can understand why things are happening, and cause/effect.

The Freshwater system says target of 7.4 on PH (with range of 7.2-7.8).  Is there a reason/benefit to aiming for 7.6 instead?

They also recommend FC of 3, with range of 1-5.  I know I've read in the past @waterbearthat you and others recommend a slightly higher FC?  Would running a higher FC be detrimental to the salt system, other than a higher demand and shorter life of the cartridge?

[waterbear]

13 hours ago, DownEastSpa said:

Is there a reason/benefit to aiming for 7.6 instead?

slower pH rise

https://www.poolspaforum.com/forum/index.php?/topic/52522-some-truths-about-ph-and-ta/

[waterbear]

13 hours ago, DownEastSpa said:

Would running a higher FC be detrimental to the salt system, other than a higher demand and shorter life of the cartridge?

The higher FC recommendation is based on having CYA in the water. Having 30 ppm CYA will allow you to maintain a slightly higher FC level with less on time of the salt cell and therefore extending the life of the cell. With no CYA a FC level of 1 to 3 ppm is adequate but the chlorine is more aggressive to swimsuits and spa parts then running 30 ppm CYA and a FC level of 3 to 6 ppm.

[DownEastSpa]

7 hours ago, waterbear said:

The higher FC recommendation is based on having CYA in the water. Having 30 ppm CYA will allow you to maintain a slightly higher FC level with less on time of the salt cell and therefore extending the life of the cell. With no CYA a FC level of 1 to 3 ppm is adequate but the chlorine is more aggressive to swimsuits and spa parts then running 30 ppm CYA and a FC level of 3 to 6 ppm.

Thanks again @waterbearfor the info.   

 

While I'm picking your talented brain, a couple more quick questions.

My CC has bounced between .6 and .8 my last few water checks in the past week or so.

Other numbers - 

PH -7.6,    TA - 60,    FC- 4.6,   CC - .6 or .8

CYA - 60

CH - 50

water is 3 months old, using Freshwater Salt system (salt at rec. levels)

My concern is should I do a shock to try and knock the CC down/out?  No major smells to the water and crystal clear looking.  Obviously a bit of a clean chlorine smell when the cover is first opened.    My wife and I took a 1-hour soak the other night and I thought perhaps the water and our bodies had a bit more of a chlorine smell after the soak than in the past.  I realize this is normal for a long soak, and I probably should have hit the tub with a bit of bleach after the soak, but was a bit wine-fuddled.  Morning after FC was 1.6 and by boosting the salt to 10 was back to 4.6 that afternoon.  I normally boost system to 10 an hour or 2 ahead of time when I know more than 1 person is going in, but forgot on this one.

We leave for vacation saturday for a week away, so I'm really hesitant to shock this now and then try and catch the FC and PH, etc all within a day before vacation.  The hot tub can go for a week without opening the cover and the salt sytem maintains 3-5ppm FC (thanks Covid for allowing me to unwillingly test that last month!), so I'm thinking this should be fine to be dealt with when we return?

Also, I see recommendations of 10x CC level for a shock to break down the CC?  In other words up to 8ppm?  Or do I need to go higher because of my CYA of 60?  Again, CYA will be fixed with a drain in a few weeks when weather warms up (-2F this morning!)

If I do a shock to break this CC down, do I shut off the Salt system completely, and then turn back on when FC levels fall back to 3-5?

thanks again!

 

 

[waterbear]

2 hours ago, DownEastSpa said:

My CC has bounced between .6 and .8 my last few water checks in the past week or so.

When persistent CC is above .5 ppm you need to shock. More on that in a bit. Also, instead of using a 25 ml. sample for the chlorine tests with the K-2006 use a 10 ml sample. You really don't need a precision of .2 ppm.

2 hours ago, DownEastSpa said:

CYA - 60

With a CYA of 60 and persistent CC I would run the FC in the 5 to 9 range. with a target of 6 or 7 ppm. To help oxidize the CC shock with bleach to a level of 15 to 20 ppm. Let the FC drop to below 10 before entering the tub and keep the tub uncovered until the FC has dropped. You can leave the salt system on when you shock since it's also producing bleach (sodium hypochlorite) or turn it off (but make sure to turn it back on to maintain your FC level.

You might be able to get rid of the CC or get it to .5 ppm or lower by running your FC higher for a week or two so try that before you shock.

2 hours ago, DownEastSpa said:

Morning after FC was 1.6 and by boosting the salt to 10 was back to 4.6 that afternoon. 

"Boosting" is shocking. A better term for shocking is superchlorinating.

 

2 hours ago, DownEastSpa said:

I see recommendations of 10x CC level for a shock to break down the CC? 

ONLY if there is NO CYA present.

 

2 hours ago, DownEastSpa said:

If I do a shock to break this CC down, do I shut off the Salt system completely

You can but it's not necessary. I don't.

Here is some info on bleach dosing:

https://www.poolspaforum.com/forum/index.php?/topic/53108-some-truths-on-bleach-dosing/

 

[DownEastSpa]

31 minutes ago, waterbear said:

 

 

"Boosting" is shocking. A better term for shocking is superchlorinating.

 

ONLY if there is NO CYA present.

 

 

 

Sorry should have clarified when I said boosting, I meant turning on the Boost Function on my Freshwater Salt system, which basically turns it automatically to 10 out of 10 for chlorine output for 24hrs.  I physically did not add anything to tub.

I'm a bit confused how the 10x CC shock level works if it's to only be used when CYA is zero??  10x zero is still zero, right?  

How long uncovered (ballpark) will it take for a shocked spa to come down under 10fc from shocked level of 15-20fc? Weather is a bit cold for me to leave tub uncovered for a day, or overnight, or several hours.  Does aeration help the shock-level FC come down quicker, or should that be avoided due to pH rise (I know ph will be a bit up anyways from bleach shocking)?

[waterbear]

25 minutes ago, DownEastSpa said:

Sorry should have clarified when I said boosting, I meant turning on the Boost Function on my Freshwater Salt system, which basically turns it automatically to 10 out of 10 for chlorine output for 24hrs.  I physically did not add anything to tub.

shock is a verb, not a noun. It's something you do (raising the FC level (superchlorinating), so a specific product. The source of chlorine does not matter. It can come from adding a product of running the salt generator at full power for 24 hours. In either case you are raising the FC level above normal. You are adding additional chlorine to the tub in either case so , yes, you are adding something to the tub when you boost. Your cell is creating sodium bypchlorite by the electrolysis of salt in the water. Sodium hypochlorite is bleach. By boosting you are adding additional beach to your water.

30 minutes ago, DownEastSpa said:

I'm a bit confused how the 10x CC shock level works if it's to only be used when CYA is zero??  10x zero is still zero, right

??? I think you are confusing CC (combined chloramines) with CYA (cyanuric acid)

 

 

51 minutes ago, DownEastSpa said:

Does aeration help the shock-level FC come down quicke

. If there is no CYA then superchlorinating to 10x the CC will usually be high enough. IF there is .5 ppm CC then shocking to .5 x 10 = 5 ppm FC is good. IF there is 0 ppm CC then 0 x 10 = 0 FC is needed (no shocking needed). IF CC is 2 ppm then 2 x 10 -= 20 ppm is needed.

Once CYA is in the water the amount needed changes because of the complex interaction between CYA and chlorine and the above rule does not apply. IF there is CYA present then shock level is approx 40% of the CYA level for manual chlorination. With a salt system a lower shock level will work because of the very high FC levels in the vicinity of the salt cell (a small portion of the water is constantly being shocked). Therefor the recommendation of 15 to 20 ppm should be adequate. IF there is still persistent CC over .5 ppm then different tactics can be employed but most of the time the above recommendation should work.

44 minutes ago, DownEastSpa said:

How long uncovered (ballpark) will it take for a shocked spa to come down under 10fc from shocked level of 15-20fc?

Hard to say. Depends on the organic load and disinfection byproducts that need to be oxidized. Leaving the tub uncovered accomplishes a few things: 1. it protects the cover from damage by the high chlorine level2. it allows the oxidation byproducts to gas out of the water.

50 minutes ago, DownEastSpa said:

Does aeration help the shock-level FC come down quicker,

yes

52 minutes ago, DownEastSpa said:

or should that be avoided due to pH rise

no, pH rise should be non existent or minimal with your low TA

53 minutes ago, DownEastSpa said:

I know ph will be a bit up anyways from bleach shocking)

No, it won't. Bleach is pH neutral Alkaline on addition but has an acidic reaction when it oxidizes for a net pH neutral effect on the water. The only thing it will add is salt as it is consumed. This is why the salt level for your generator stays stable and only needs to be replenished because of splash out. The salt keeps regenerating. (oversimplified chemistry by basically true)

HOWEVER, AND THIS IS IMPORTANT!!!!! pH will appear to have gone up when sanitizer levels are high. Never test pH when FC levels are above 10 ppm with Taylor reagents. Other pH tests often will read high at 5 ppm FC or even less. The indicator dye used (phenol red) converts to chorophenol red when FC is high. Chlorophenol red is an indicator dye that changes color from yellow to violet in the pH range 4.8 to 6.7 (same color change as phenol red but at a lower pH range so when it shows the purple color it means that your pH is somewhere above 6.7 but there is no way to tell just how much above 6.7 it is. Taylor includes an inhibitor in their phenol red to allow it to work at higher FC levels but most other manufacturers do not. Bottom line, never try to test pH when sanitizer is above 10 ppm.

[DownEastSpa]

Thanks for all of the info, and you're right - I was having a brain cramp on the 10xcc formula with no cya. 

[DownEastSpa]

Huge thanks to @waterbear for the advice above. We were gone on vacation for last week, and before we left I bumped fc up with bleach to 5ppm, and I left Freshwater System on 5/10 while we were gone after making sure ph/ta etc were all in line.

This morning upon returning fc was at 6, and Cc was .5 at most (barest hint of pink on cc test and instantly gone with 1 drop on 2006 kit). So, waterbear was dead on with his advice of bumping the fc for a week or so to bust the cc down from 1 to .5

Also, ph and ta never moved during the week we were gone. Ph 7.6 and ta of 60. Seems like I'm dialed in and merely need to boost salt system or add additional bleach based on bather load.