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Low Alkalinity pair with High pH - HELP PLEASE!


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Hello, 

I am new here, so I apologize if this top was already covered plenty of times, but when I fill my hot tub, my water tends to start with a high pH level around 8 or above and a low TA around 50ppm. My MFG guideline for my 300 gallon hot tub is TA between 80 and 120ppm and pH between 7.2-7.8 (ideally 7.4-7.6). I always start by raising the TA up to about 100ppm using Sodium Bicarbonate, then I move to Calcium hardness (which is initially low with my water source, so I wait a day after raising the Alkalinity, then I raise hardness) to about 190-200ppm. After that, my next step is pH. After raising the Alkalinity to the proper range, my pH is now even higher than it started, so I need to lower that using Sodium Bisulfate. That generally takes a few additions of about 1/2 of this product to get me in the 7.4-7.6 range. 

This is where I run into my issue where once I get the pH lowered to the ideal 7.4-7.6 range, the alkalinity is back on the low end (around 60-70ppm), then if I raise that, the pH goes up and beyond the ideal range again, so I seem to be in a never ending cycle of either having slightly elevated pH or slightly low TA. My main question being, is there a different product I should use to either raise my TA or lower my pH without having knocking the other out of range? If the chemicals I am using are fine, is one less of an issue than the other? For example, is it better for me to have an ideal TA with a slightly elevated pH or have a TA around 60-70ppm with a perfect pH reading? 

For water testing I use a Taylor kit  (Taylor Complete K-2006 Kit) with the droppers to identify my pH, hardness, TA, and free/combined chlorine readings. Perhaps the test kit is my issue, but I have read these are pretty darn accurate and I have gotten a wide variety of poor results trying to use basic test strips, so I don't trust those. Any thoughts or suggestions would be appreciated!! 

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I will be interested in the answers as I have the exact same problem. Only my TA tends to be about 40 ppm. 

 I have found I can raise the alkalinity above where I need it and then when I lower the pH , the product acts more on the pH than the alkalinity , so hopefully the TA doesn’t drop TOO low.

Someone on these boards told me to worry more about the pH and not be so concerned if the TA is 40-50. 

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I'm on well water so I have hardness issues. 

What I do is get my hardness set first. Don't worry about anything else until the hardness is right. Once it's right, I then move to TA. TA of 50 is certainly low but it's OK. I typically run a TA of 120-150. Once the TA is up for snuff (when I know the pH is high, I'll try to hit that 150 mark for TA and let it drop to 120 fixing the pH), then I worry about pH. 

I have the Frog@ease system so I run a free chlorine level between .5-1 ppm (which is the level recommended by King). The TC usually runs around 4-5 ppm but King says the Frog system doesn't worry about TC. The hardness is right around 150 ppm, TA is in the 125 ppm range and pH is at 7.5.

310 gal tub.

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I appreciate the feedback from you both! I have tried Susanj's method of elevating the TA then reducing the pH and hoping the TA doesn't go too low, but I was just curious if there was a better method because that results in using a lot of extra chemicals to elevate then reduce both levels. Cranbiz, my hardness level is good as we speak, but I still have the same issue. The only way I have gotten close to having it all in range was to do what SusanJ suggested with raising the TA slightly over the suggested range, then when I reduce pH I hope the pH level falls quicker than the TA level. 

I will attempt both of your suggestions and continue to monitor this to see if anyone else has any tricks/tips on the subject. Thanks again! 

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Read both these pinned posts. They explain some of the basics about pH and TA and the PROPER way to lower TA.

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

https://www.poolspaforum.com/forum/index.php?/topic/28846-lowering-total-alkalinity-howto/

Also realize that a TA in the range of 50 to 70 ppm works out best for most people in terms of pH stability because of the high amount of aeration in spas, which causes more outgassing of CO2 which causes the pH to rise!

Also, TA will move with pH, it's the nature of the beast. Get your pH in line first (no lower than 7.6) and then adjust TA if it is not in the 50 to 70 ppm range. When pH climbs ABOVE 7.8 drop it back down to 7.6. Adding borate to 50 ppm will create a secondary borate/boric acid buffer that, in conjunction with the bicarbonate, carbonic acid buffer we call TA "locks" the pH at around 7.7 for a longer time than with out the borate. (Borate also has algaestaic properties and is a safey net if santizer levels drop. It also improves the "feel" of the water.

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2 hours ago, Susanj said:

But it’s not lowering TA we are concerned about. It’s raising it without raising pH too much. 

Question, what sanitizer are you using and are you using a non chlorine shock ? Some sanitizers can cause TA to drop quickly such as trichlor, which is NOT a good choice for a hot tub for several reasons, and non chlorine shock can also deplete TA.

My advice is to get the pH to between 7.6 and 7.8 then test your TA.  If pH is low aerate to raise it. DO NOT USE pH increaser.

If it is high use acid (dry or muriatic) to lower it

Test TA. If it is below 60 ppm then add baking soda to bring it up. 1/2 tablespoon will raise 100 gallons approx. 10 ppm. 

recheck pH, it should not have moved much. If it has bring it in line to 7.6 to 7.8 and recheck TA. Sometimes this needs to be 2 or 3 times but it usually is in the ballpark the first time.

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2 hours ago, Susanj said:

Might you explain the difference between borate, boric acid and Borax?

Can all be purchased and which do you use in a hot tub? Thanks! 
 

Boric acid (ordered online from a chemical supply, Amazon, Candle and soapmaking supplier, etc.),  Sodium Tetraborate Pentahydrate (found in commercial products for pools and spas), and Sodium Tetraborate Decahydrate (found in the laundry aisle of your grocery store with 20 Mule Team on the box) all will add borate ions to the water to create the borate/boric acid buffer. of Any one can be used successfully, however the dosing and procedure is different for each. Give me a few days and I will write a post and pin it in the Hot Tub Water Chemistry section of the forum. The only difference between the pentadrate form and the decahydrate form is that the pentahydrate has 5 water molecules attached and the decahydrate has 10 water molecules attached so the pentahydrate form will need slightly less by weight to product the same ppm concentration of borate as the decahydrate.

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8 minutes ago, Susanj said:

why is it that I read over and over to check TA first and get that in line first before the others? 

And how has that been working for you? 😉 TA will move with pH. Get your pH in the ballpark first then adjust the TA. 1by doing this you will get a more accurate TA reading at the desired pH and can then adjust the TA from there. IF the TA needs major adjustment upward the pH will go up but usually if you bring it down to target the TA is still in the desired range.

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Dichlor. This is a vacation rental and I don't trust guests with bleach. I just started leaving containers for them to use,  with 1 Tb dichlor  to put in at the end of the day because each time we check after they leave  (we are 1 1/2 hrs away but our cleaner does it too) the sanitizer has been reading 0

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The problem with dichlor is  that it adds CYA at a rate of 9 ppm for every 10 ppm FC added and the tub will quickly become overstabiliized. This could lead to pseudomonas infections or enteric pathogens flourishing in the water and could possibly leave you open to liability for any medical expenses. You might want to consider a silver/MPS system like Nature 2 as long as the tub is not turned off because silver and MPS are are only a sanitizer in hot water. Nature 2 can also be used with dichlor instead of MPS. The silver does provided some additional protection when used with dichlor.

Dichlor is only mildly acidic so it should not cause your TA to crash and it should remain fairly stable in the 50 to 70 ppm range.

Realize that if you are using chlorine  it really needs to be added daily in most cases to maintain the FC level (trichlor tabs in a floater are not recommend for tubs because they are extremely acidic and reaquire constant monitoring of and I suspect that there are times that days might go by between rentals where the tub just sits there.

 

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King Technologies has 2 systems for hot tubs. The original SpaFrog (now called Frog Serene) is a bromine only system and not designed to work with dichlor. The second system Frog@EASE is a a chlorine based system but the chlorine source is their proprietary SmarChlor (1,3-dichloro-5,5-dimethylhydantoin) which tests as combined chlorine. Once again this system is not compatible with dichlor. 1,3-dichloro-5,5-dimethylhydantoin is not normally used as a chlorine source in pools and spas.

Nature 2 by Zodiac is used with either MPS (as long as the spa is kept heated constantly) or with dichor.

If you were using bromine a floater is fine, just not with chlorine.

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King Technologies told me to use dichlor at start -up with the bromine Serene system and then to shock with MPS. 

For the chlorine in-line At Ease system , they say to use Dichlor at start up and preferably Dichlor shock. You can use MPS to shock but apparently it may give you a false high chlorine reading for a few days. 

when I asked what exactly was in the chlorine cartridge , I was told Dichlor. 
 

Before I used the Frog system, I used a bromine floater and I could use either Dichlor or MPS to shock. 
 

 

 

 

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MPS is more acidic than dichlor and can deplete the TA much faster.

 

 

7 hours ago, Susanj said:

when I asked what exactly was in the chlorine cartridge , I was told Dichlor. 

Not according to the SDS for SmartChlor, it's 1.3-dichloro-5, 5-Dimethylhydantoin ......... 81.1%  and 1.3-dichloro-5-ethyl-5-methylhydantoin .... 16.1%

https://www.kingtechnology.com/sds/@ease_SmartChlor_Cartridge_R1-10092018.pdf

 

King Technology does have the FilterMate that can be used with either bromine or dichlor but the Frog@EASE system uses their proprietary SmartChlor, which will test high CC, similar to MPS. However if you are using a Taylor K-2006 there is an add on to that kit that will allow you to removed the interfertence from MPS to get accurate FC and CC readings. How are you testing your water\ and exactly which King system are you using (SpaFrog/FrogSERENE, FilterMate, or Frog@EASE)?

 

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20 hours ago, Susanj said:

I'm using the Frog At Ease.

According to King Technology and their instructions for this system you should not need to add additional chlorine once it is adjusted properly.

20 hours ago, Susanj said:

I have the TF-100 and also the Taylor K-2006.

If you are using the SmartChlor cartridge then you do not want to test CC since it will read high because of the dimethylhydantoin carrier for the chlorine.

However, your problem with FC reading 0 ppm is illustrative of why I do not like metal or 'mineral systems that advocate using very low FC levels that leave nothing in reserve and are quickly depleted. (Call them minerals if it makes you feel warm and fuzzy but the truth is that you are adding metal ions to the water, which have very slow kill times, and are ineffective against viruses) You stated the problem in the quote below.

On 8/5/2021 at 6:40 PM, Susanj said:

dichlor  to put in at the end of the day because each time we check after they leave  (we are 1 1/2 hrs away but our cleaner does it too) the sanitizer has been reading 0

 

FWIW, the Nature 2 system WHEN USED WITH CHLORINE AND NOT MPS does come close to using normal chlorine levels and not the .5 to 1. ppm that King Technology promotes (and the Nature 2 used to promote) Both companies promote these low levels with their swimming pool products but they also add copper into the mix.making these systems just another copper/silver ion system. Copper is left out of the spa systems because copper and hot water is a recipe for green hair! (easily removed with photographer's hypo aka sodium thiosulfate and citric acid if you know what you are doing (a secret known to advanced hair colorists, btw). I am also a licensed barber and cosmetologist (over 40 years now and still licensed) and worked as a colorist for many years when I was younger. I once worked in an exclusive day spa in Miami that had a hot tub. The service company kept dosing it with a copper based algaecide and we had several clients who came out with bright green hair at various times. The owners freaked the first time it happened until I told them I could remove the green with 2 simple ingredients and saved them from a lawsuit. I also told them that they needed to fire the service company taking care of the hot tub but they didn't so the problems occurred more times than I care to think about.)

A fun fact, Citric acid is one of the chemicals used to remove metal staining from pool and spa surfaces along with ascorbic and oxalic (which is toxic so it's not my first choice, even though at least one pool product company sell it for this purpose) after dropping the FC levels to less than 1 ppm with sodium thiosulfate.

 

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Frog@EASE Is compatible with dichlor BUT you have to dose sparingly or your CYA will climb. I had cloudy water issues with MPS (everything was within proper limits) and no issues with water clarity with dichlor shocking once a week. That frequency keeps the CYA in check, anything more than that, your CYA will quickly get out of hand. MPS won't give you any CYA so that's why King recommends it, it does work, but I had issues which could have been on me as I'm still learning water maintenance.

The Frog@EASE starter pack is dichlor, so I'm calling BS on dichlor not being compatible.

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Ok, so I am trying to take all of this in as there is a lot of different info/chemicals being recommended, but the one thing I do use is non-chlorine shock and based on some of the discussion it seems like you recommend shocking with Chlorine/Dichlor (which is what I use for chlorine/sanitizer in my hot tub currently). Should I just do away with the non-chlorine shock and just use the chlorine as shock after uses and once per week? I actually use the Nature 2 Spa stick as well, but that is just in addition to the chlorine I add, so it's not my stand alone sanitizer. 

When I do get my pH balanced it seems my TA only falls to about 60, so I guess I can just let it hover around 60ppm as long as my pH is below 7.8, and not lower than 7.6...?

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1 minute ago, DelcoHotTub5518 said:

When I do get my pH balanced it seems my TA only falls to about 60, so I guess I can just let it hover around 60ppm as long as my pH is below 7.8, and not lower than 7.6...?

Yes, the aeration from the jets will cause pH to rise. Lower TA helps counteract that. If you are using MPS, which is acidic monitor the TA and it drops below 50 ppm bump it back up toe 60 or 70 ppm. I would test TA weekly until you have an idea of how quickly it drops but don't go longer than monthly for testing it.

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7 hours ago, cranbiz said:

The Frog@EASE starter pack is dichlor, so I'm calling BS on dichlor not being compatible

You are correct that the Jump Start is diclor, along with citric acid and 'inert ingredients' (my guess  is baking soda so it effervesces when the citric acid and the baking soda dissolve).

 However, the point you are missing is that it is added BEFORE the Frog@ease with the SmartChlor is put into the tub to create the initial FC level. Once dissolved in the water you have hypochlorite ions and a very small amount CYA. SmartChlor is a stabilized chlorine that uses dimethyhydantion to stabilize the chlorine instead of CYA and it works differently since it tests as mostly combined chlorine and releases the FC slowly and at a very reduced rate to maintain a .5 to 1 ppm FC level in the ater. A stabilized chlorine source like dichlor is not added continuously after the initial fill as normal maintenance or shocking along with the SmartChlor and whether there are any adverse affects on water sanitation with the continued addition of CYA is an unknown since King does not publish that data but their website and instructions for Frog@ease does say that Jump Start is only used on fresh fills before the system is put into the water. In fact, King recommends turning up the dial to release more SmartChor if the water is cloudy and not shocking with dichlor.

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