Fighting raising PH level and low alkalinity - saltwater pool

Feb 12, 2024
15
Debary, Florida
I have a saltwater pool - constantly adding muriatic acid to lower PH levels, which lowers total alkalinity. Previously posted about this and was told 50-60 total alkalinity is good even though manual says to keep it between 80-120. Total Alkalinity is now down to 30. Should I now add baking soda to raise the total alkalinity and how do I do so with the constant increasing PH levels? Add baking soda, then acid, then baking soda, until alkalinity gets back up to like what, 60-70 range? Will that work? Below are rest of my test results. (Testing with TF-Pro kit)

FC - 5 ppm
Calcium Hardness - 300 ppm
Total Alkalinity - 30
PH level - 7.4 at the moment
CYA - 30-40
Salt - 3600 ppm
 
What type of pool surface? Plaster, vinyl, fiberglass?
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TA is too low; you'll need to raise it. pH drift is uncommon when TA is in a good place, so somehow you've gone past that point, but there might be other reasons.

My plaster pool stops pH rise with TA 50-60. Are you trying to manage CSI or trying to manage to a specific pH that's causing you to keep adding acid resulting in low TA?
 
What type of pool surface? Plaster, vinyl, fiberglass?
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TA is too low; you'll need to raise it. pH drift is uncommon when TA is in a good place, so somehow you've gone past that point, but there might be other reasons.

My plaster pool stops pH rise with TA 50-60. Are you trying to manage CSI or trying to manage to a specific pH that's causing you to keep adding acid resulting in low TA?
My PH levels rise very quickly. Have to add muriatic acid every couple days. My understanding is that this is common with saltwater pools, especially newer pools. Was told to only add a little acid at a time to keep PH level in the high 7s and this will help stabilize. Do my best with that but still have to add acid every couple days....Oh and my TA was at like 110 and has been decreasing ever since, which is expected after adding the acid. At no TA level has my pH levels not constantly risen.
 
My PH levels rise very quickly. Have to add muriatic acid every couple days. My understanding is that this is common with saltwater pools, especially newer pools. Was told to only add a little acid at a time to keep PH level in the high 7s and this will help stabilize. Do my best with that but still have to add acid every couple days....Oh and my TA was at like 110 and has been decreasing ever since, which is expected after adding the acid. At no TA level has my pH levels not constantly risen.
Plaster pool
 
New plaster - ok.
Your SWCG is not causing pH changes or acid demand. When you say your pH levels are rising quickly, at what pH are you adding acid?
I would not be adding any acid until pH rises above 8.

Get that signature created and I'd really recommend logging in PoolMath so that everyone can see your testing results.
 
New plaster - ok.
Your SWCG is not causing pH changes or acid demand. When you say your pH levels are rising quickly, at what pH are you adding acid?
I would not be adding any acid until pH rises above 8.

Get that signature created and I'd really recommend logging in PoolMath so that everyone can see your testing results.
Hmm I think it's quite common for SWG owners to have to constantly add acid. I've heard this from numerous people and I researched it myself. Maybe I'm wrong? My pH level flies by 8. It's at 7.4 now, it'll be over 8 in a couple days
 
It's not the SWG but rather the plaster pool that causes this, generally. A new pool, replastered pool or acid washed pool will cause high PH for 1 to 2 years after the new finish is done. Do you fall into one of those categories?
 
I've seen people drive themselves mad by trying to micromanage their pH, which also tanks their TA due to the frequent acid additions.

Any pH in the 7's is fine and 8.0 is fine too. My water loves to hang out in the 7.8-8.0 range so I let it and I can go weeks/months without adding MA. If I tried to keep it at 7.4 I would drive myself crazy. Here is my pH treatment plan:

Day 1: 8.0+ - Add acid to drop it to 7.4
Day 2: My pH will stay at 7.4 then in the blink of an eye be back to 7.6
Day 4/5: I'll be back to 7.8 and I resist the urge to knock it back down to 7.4.
1-2 weeks later: My pH will have crept up to 8.0. Assuming I can test on a regular basis, I still resist the urge to add acid.
1-3 weeks later: My pH will finally test above 8.0 so I knock it down to 7.4 and repeat the process.

The above keeps me sane and limits my MA additions. Hope that helps.
 

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Hmm I think it's quite common for SWG owners to have to constantly add acid. I've heard this from numerous people and I researched it myself. Maybe I'm wrong? My pH level flies by 8. It's at 7.4 now, it'll be over 8 in a couple days
You’ll get different answers on here about SWG and PH. I have a plaster pool and a SWG. While the SWG doesn’t cause the PH to rise per se, PH rises faster and more consistently with SWG pools. All pools PH rise on their own. The chlorine tabs are acidic, so they lower your PH. So those who chlorinate with tabs (most people) don’t have to worry as much about PH rising because the tabs are lowering it.

I got a SWG for many reasons, one was ease of maintenance. After it was built, I was continually adding acid which made it more mainlanders then I was hoping. So.. I added an acid inject tank (Pentair IntelliPH), and it’s awesome!
 
You’ll get different answers on here about SWG and PH. I have a plaster pool and a SWG. While the SWG doesn’t cause the PH to rise per se, PH rises faster and more consistently with SWG pools. All pools PH rise on their own. The chlorine tabs are acidic, so they lower your PH. So those who chlorinate with tabs (most people) don’t have to worry as much about PH rising because the tabs are lowering it.

I got a SWG for many reasons, one was ease of maintenance. After it was built, I was continually adding acid which made it more mainlanders then I was hoping. So.. I added an acid inject tank (Pentair IntelliPH), and it’s awesome!
Interesting! I'll have to look into that, I have all pentair equipment. Hopefully it's true that it's rising so fast because my plaster is new and as time goes on I won't have to add acid so much
 
After it was built, I was continually adding acid which made it more mainlanders then I was hoping. So.. I added an acid inject tank (Pentair IntelliPH), and it’s awesome!
Your acid demand is because your fill water TA is higher than your pool water. It's not the SWCG as electrolysis does not induce pH change.
My well water TA is 200-250 and several municipal supplies we've seen are ~150 TA.
 
No, when solution turns red/purple to blue I stop
Blue? Normally green to red.

Also, adjust pH only when required to get you CSI back into your targeted range. I normally add MA to bring CSI down to around -0.03 -0.30 and let it slowly rise to just above 0.00. For me currently that's 7 to 10 days with a TA of 50 (don't go lower). SWG with plaster coming up on its first birthday.

Total Alkalinity Test
1. Rinse and fill the clear plastic cylinder to the 25ml mark
2. Add two drops of R-0007 and mix. Then, add 5 drops of R-0008 and mix again. Solution will turn green.
3. Add R-0009 one drop at a time, swirling between each drop. Wipe the tip of the bottle after every drop with a damp cloth. Continue ‘til color changes to red. Multiply the number of drops you added times 10. (11 drops = T/A 110) Record it. TA can vary widely. but a range of 70-120 normally works well.

NOTE: In the presence of high chlorine, initial color may be blue and shift to yellow. Test is still valid.
 
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Blue? Normally green to red.

Also, adjust pH only when required to get you CSI back into your targeted range. I normally add MA to bring CSI down to around -0.03 and let it slowly rise to just above 0.00. For me currently that's 7 to 10 days with a TA of 50 (don't go lower). SWG with plaster coming up on its first birthday.

Total Alkalinity Test
1. Rinse and fill the clear plastic cylinder to the 25ml mark
2. Add two drops of R-0007 and mix. Then, add 5 drops of R-0008 and mix again. Solution will turn green.
3. Add R-0009 one drop at a time, swirling between each drop. Wipe the tip of the bottle after every drop with a damp cloth. Continue ‘til color changes to red. Multiply the number of drops you added times 10. (11 drops = T/A 110) Record it. TA can vary widely. but a range of 70-120 normally works well.

NOTE: In the presence of high chlorine, initial color may be blue and shift to yellow. Test is still valid.
Yeah my fault I was referring to the calcium test.
 
Your acid demand is because your fill water TA is higher than your pool water. It's not the SWCG as electrolysis does not induce pH change.
My well water TA is 200-250 and several municipal supplies we've seen are ~150 TA.
It is not. My fill water TA is around 60, as is my pool. I already said the SWCG is not to blame, it’s the absence of acid tabs that normally keeps the PH in check.

So, from a pool owners perspective, what’s the difference? A pool with a SWCG will tend to have a higher PH than a pool chlorinated with CYA filled tabs. A new plaster pool, higher still.

An acid injection tank plus a SWCG is a great setup.
 
It is not. My fill water TA is around 60, as is my pool. I already said the SWCG is not to blame, it’s the absence of acid tabs that normally keeps the PH in check.

So, from a pool owners perspective, what’s the difference? A pool with a SWCG will tend to have a higher PH than a pool chlorinated with CYA filled tabs. A new plaster pool, higher still.

An acid injection tank plus a SWCG is a great setup.
Nobody has really answered my question. One person says it's because of my newer plaster which is reassuring because hopefully eventually I don't have to constantly add acid. But unless there's an underlying issue, I don't really care WHY I have to constantly add acid. My question is do I need to increase the TA from 30 and to how high and then what's the best way to do so. Will adding baking soda to increase TA (which will also increase pH meaning I'll have to add acid which will lower TA which means I'll have to add baking soda lol) do I just repeat that process and eventually the TA will rise all the while keeping my pH level under control. Seems like nobody really knows the answer, so I think I'm just going to try that out.
 

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