Hi all - looking for some ideas as we get into full swing on our 2nd summer with our new pool. Since switching over to the salt cell last summer, I've been maintaining the pool myself and its been going well. I've noticed after coming out of the cold weather and into Spring and early summer, I've been having to turn my salt cell up higher, but it doesn't seem to really increase my FC significantly. On top of that, every time I bring my pH down (w/ Muriatic acid) it isn't long before its right back up again. I also have the white calcium flakes coming through the jets, settling on the pool floor, which I vacuum up pretty quickly as I am pretty regular on brushing, skimming, and vacuuming. No other real issues I've noticed (yet) with the pool, but I'm basically in this cycle of dosing the pool with a good amount of Muriatic acid to get the pH down, then setting my salt cell on "boost" which runs it at 100% for at least an 8 hour pump cycle to get my FC up. Within a couple days, I check readings and they are similar to what I've attached here, which was taken earlier this evening. The last time through this cycle, rather than kick up my salt cell to 100%, I left it alone and dosed the pool with liquid chlorine to get my FC up to where I wanted it (around 5-6ppm). What else can I share? I have cleaned my salt cell at the start of the summer, and my filter pressure is checking out okay (though I do believe a filter rinse/clean is due, which I may tackle this weekend along with any recommendations you all may have). I really appreciate any input, and while I know some level of higher pH and even these calcium flakes comes with the territory having a salt water pool (from what I've read here anyway), I feel like things were a bit more stable last summer and I'd certainly like them to be! Again thanks!
Looking for Guidance: 1yr in - Salt Pool, pH keeps going high, TC doesn't stay high
- Thread starter NE_POOLGUY
- Start date
- Mar 5, 2020
- 3,069
- Pool Size
- 66000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral Viron V35
Welcome Poolguy, and congrats on the first post.
To a certain degree it's normal that you need to keep cranking up the SWG going through spring into summer. But having had your FC below the min for your CYA (see FC/CYA Levels), you likely have algae lurking that you are just able to suppress enough to stop them from blooming, and that's eating your chlorine. Best to do an Overnight Chlorine Loss Test to get a baseline.
Regarding the flakes, your TA is relatively high, which will be enough to create quite a positive CSI with your CH (which on its own isn't bad) when your pH spikes up. This will create scaling in your SWG cell that gets ejected into the pool during cell reversal.
You should turn on Temperature and CSI tracking in PoolMath.
The high TA is also responsible for the fast pH rise. High TA means high amount of carbonates dissolved in the water that want to outgass and drive the pH up in doing so.
What's the TA of your fill water, I suspect quite high?
But first things first. Most important to deal with the algae, which I highly expect to be lurking. I would turn off the SWG for now and use liquid chlorine until we have that settled.
Start with the Overnight Chlorine Loss Test.
Depending on the outcome you will likely have to follow the SLAM Process.
Have a good read through the linked articles. Before starting a SLAM, make sure to not ignore the bit about lowering pH first.
Once that's all dealt with, we can start tackling your TA.
Don't worry, you've got this, and there a lots of helpers around here to guide you through the process.
To a certain degree it's normal that you need to keep cranking up the SWG going through spring into summer. But having had your FC below the min for your CYA (see FC/CYA Levels), you likely have algae lurking that you are just able to suppress enough to stop them from blooming, and that's eating your chlorine. Best to do an Overnight Chlorine Loss Test to get a baseline.
Regarding the flakes, your TA is relatively high, which will be enough to create quite a positive CSI with your CH (which on its own isn't bad) when your pH spikes up. This will create scaling in your SWG cell that gets ejected into the pool during cell reversal.
You should turn on Temperature and CSI tracking in PoolMath.
The high TA is also responsible for the fast pH rise. High TA means high amount of carbonates dissolved in the water that want to outgass and drive the pH up in doing so.
What's the TA of your fill water, I suspect quite high?
But first things first. Most important to deal with the algae, which I highly expect to be lurking. I would turn off the SWG for now and use liquid chlorine until we have that settled.
Start with the Overnight Chlorine Loss Test.
Depending on the outcome you will likely have to follow the SLAM Process.
Have a good read through the linked articles. Before starting a SLAM, make sure to not ignore the bit about lowering pH first.
Once that's all dealt with, we can start tackling your TA.
Don't worry, you've got this, and there a lots of helpers around here to guide you through the process.
MGTFP: Thanks for the detailed reply, was exactly the type of guidance and info I was hoping to get back. I'll read through the linked articles and get working on this right away. Btw, my mother was an Aussie, she was born and raised not far from Melbourne (Ballarat to be specific). G'day!
- Mar 5, 2020
- 3,069
- Pool Size
- 66000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral Viron V35
So I did my overnight chlorine loss test, here were my numbers (note: I added liquid chlorine 2-3 hours prior to sundown to ensure I was up above at least 3ppm for the test):
Anyway, I had some delay in posting these results - had the weekend sneak up on me and so things got busy. Very much appreciate any guidance from here. Thanks all for the time!
- 8:50pm (this is after sundown), recorded: 4.5ppm FC
- 11:15pm (2nd after dark reading, to be sure my liquid chlorine had adequate time to fully mix) recorded: 3.5ppm (dropped 1ppm?!)
- 6:15am (Just prior to direct sunlight on the pool) recorded: 2.5ppm. I also tested for CC, recorded 0.5ppm.
Anyway, I had some delay in posting these results - had the weekend sneak up on me and so things got busy. Very much appreciate any guidance from here. Thanks all for the time!
- May 3, 2014
- 58,507
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
- Mar 5, 2020
- 3,069
- Pool Size
- 66000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral Viron V35
Yeah, you're up for a SLAM.
Algae usually doesn't create CC. CCs are chloramines that get created from oxidising for example bather waste.
What you observed with your night testing is well within expectation. Loss is a percentage of the FC level, do absolute loss goes down as FC goes down. And some testing error. Say your 11:15 test was 1 drop too low, then you'd overestimate the first, and underestimate the second loss.
What matters is that your chlorine loss between sunset und sunrise was 2ppm, which is clearly too much.
Algae usually doesn't create CC. CCs are chloramines that get created from oxidising for example bather waste.
What you observed with your night testing is well within expectation. Loss is a percentage of the FC level, do absolute loss goes down as FC goes down. And some testing error. Say your 11:15 test was 1 drop too low, then you'd overestimate the first, and underestimate the second loss.
What matters is that your chlorine loss between sunset und sunrise was 2ppm, which is clearly too much.
Edit: Just looking into the details on the SLAM Process, quick question. Calculator indicates my SLAM level of FC is 28ppm, due to CYA of 70. Is that doable or reaching points of being too high that it could damage other parts of the pool? I'd really prefer not to have to try to lower my CYA, its a painful process to drain the pool down like that with my setup; but if you all think it is necessary so I don't have to go so high with the FC during SLAM, please advise. Thanks!
SLAM it is - I'll report back. I'm also going to do a test on my fill water and I'll post those results when I have them as well.
SLAM it is - I'll report back. I'm also going to do a test on my fill water and I'll post those results when I have them as well.
Last edited:
- Mar 5, 2020
- 3,069
- Pool Size
- 66000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral Viron V35
CYA 70 is a big challenge for a SLAM. CYA reduction would be a way that certainly leads to success in a reasonable time and with reasonable chlorine usage.
If you decide to keep going with CYA 70 (is that confirmed, your screenshot in the first post showed CYA 60?), you will have high chlorine losses to UV and it will be a battle to keep FC at SLAM level during the day. Working night shift might help a bit. And don't forget to reduce pH to 7.2 before you start.
If you decide to keep going with CYA 70 (is that confirmed, your screenshot in the first post showed CYA 60?), you will have high chlorine losses to UV and it will be a battle to keep FC at SLAM level during the day. Working night shift might help a bit. And don't forget to reduce pH to 7.2 before you start.
Hi all - I'm working on the SLAM as we speak (had to delay starting a bit due to work travels). Wanted to ask a couple things and also provide update.
First, I confirmed that yes my CYA was in fact lower than I stated above, sorry. I retested carefully at the start of SLAM and a better estimate of my CYA is around 55-60. So, I am going forward with the slam from there, assuming a 60 CYA. I also got my pH down to 7.2 before starting - so here's my question. Obviously SLAM calls for regular monitoring of FC and maintaining that SLAM level. What about pH? Even after one evening and overnight, I'm already seeing my pH creep back up from where I started, so should I shoot to add Muriatic Acid and keep that pH low during the SLAM? I feel like that will be just as much a constant battle as keeping FC high, for some reason, as my pH seems very fluid at this phase, but I have the acid on hand and can do it if its recommended. Will do some research and searching on the forum in the meantime, but thank you for any input! Have a good one all!
First, I confirmed that yes my CYA was in fact lower than I stated above, sorry. I retested carefully at the start of SLAM and a better estimate of my CYA is around 55-60. So, I am going forward with the slam from there, assuming a 60 CYA. I also got my pH down to 7.2 before starting - so here's my question. Obviously SLAM calls for regular monitoring of FC and maintaining that SLAM level. What about pH? Even after one evening and overnight, I'm already seeing my pH creep back up from where I started, so should I shoot to add Muriatic Acid and keep that pH low during the SLAM? I feel like that will be just as much a constant battle as keeping FC high, for some reason, as my pH seems very fluid at this phase, but I have the acid on hand and can do it if its recommended. Will do some research and searching on the forum in the meantime, but thank you for any input! Have a good one all!
Well, very quick search tells me no point in worrying about pH during SLAM, just focus on the SLAM and fix pH after.
I will say though, in reading some of the search results, sounds like SLAM level chlorine should have the effect of potentially lowering the pH - at least in the couple of posts I read through. As I mentioned above, my test this morning seemed to show my pH having moved up instead after FC at SLAM level for about 10 hours. I'm not going to fret over it too much, but if anyone has any thoughts or ideas on what's going on with my pH level, I'd appreciate ideas/theories/expertise. Thanks all
I will say though, in reading some of the search results, sounds like SLAM level chlorine should have the effect of potentially lowering the pH - at least in the couple of posts I read through. As I mentioned above, my test this morning seemed to show my pH having moved up instead after FC at SLAM level for about 10 hours. I'm not going to fret over it too much, but if anyone has any thoughts or ideas on what's going on with my pH level, I'd appreciate ideas/theories/expertise. Thanks all
- May 3, 2014
- 58,507
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
Test FC only during SLAM. After you are done, then when FC drops below 10 ppm, test ph and TA.