- Jul 24, 2020
- 280
- Pool Size
- 19500
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Jandy Aquapure 1400
Hi everybody!
First of all, obligatory comment to say what an awesome community this looks to be. The information, guidance and 'keep it simple' approach are all fantastic and right up my street.
So, my wife and I just bought a house that has a pool, and a really very nice one at that. We're in San Jose, CA. The pool is a gunite salt pool, approximately 20,000 gallons (based on squared off actual width/length measurements we took, and average depths taken at either end and the middle).



The pool guys say it's "their favorite pool on their route" and has always only required minimal maintenance from them, which I'm sure they say to all their owners, but who knows. With the exception of some tree fluff falling to the surface each day [probably coming to another thread in the near future - how to really accelerate the skimmer to pick up this stuff), the water is absolutely crystal clear (my frame of reference is that with still water I can clearly see the main drain 8ft down in the deep end, the textured surface, and the vacuum - would pictures help here or does that sound reasonable?).
So far, the only thing I have changed from what we inherited is I changed the timer to run the pump on low power from 9am to 6pm (with 30 minutes initial full power) to keep up chlorine production throughout the day when the sun is out, and swimming happens. The previous owners had been running the pump 4-6..30am and 6.30-9.30pm (and over half at full speed) which I thought strange given swimming and chlorine consumption happens in the daytime), and vacuum for 30 minutes each day 8.30-9am. The SWG (a Nature2 Fusion Soft) is currently set to 50%.
The day we picked up the keys I took a sample of water to the nearby Leslie's, and got these results. The water sample was taken at about midday:
FC 0.9
pH 8.4
TA 98
CH 649
CYA 24
Salt 2960
Phosphates high but who cares!
We are keeping the previous owners' pool service guys going for a month or two while I get used to things. They come weekly and have been adding acid and top-up liquid chlorine as needed based on that morning's results. They're only monitoring for pH and chlorine. I asked and sadly they have not heard of this site, although they did at least point out from the Leslie's results that the CYA could come up (but they didn't actually do it), and the phosphates could be ignored. Their methodology is entirely based on experience and feel. They also thought it was a 30K gallon pool so in a way I'm glad they weren't calculating dosages!
Last week, they recorded FC 5 and pH 8.2, and asked me to turn down the SWG from 100% to 50%.
They came again yesterday, and their test results taken at were 8am on 8/4 were:
FC 1
pH 8.2
They added liquid chlorine and acid.
Being the intrepid DIYer that I am, and based on the glowing recommendations on this forum, I acquired a TF-100 kit to get a more complete picture of the water chemistry. I also bought the salt and borates tests. The kit arrived today and I did some evening testing right before sunset:
Test taken at 7.30pm on 8/5:
FC 5.0 (both FAS-DPD and color swatch - by the way why do the instructions say the water will turn 'completely clear'? Mine went milky white in a single transition at 10 drops - 5 FC - and stayed there but never went actually transparent / clear as I would interpret those words)
CC 0
pH 7.5
CH 1250
CYA 22 (20 if I round off per the instructions)
Salt 3900
Borates 5 (not 0 but definitely not 10 from the swatch)
The two results that jump out at me are that the salt level, being 1000ppm higher than the Leslie's test result, and the CH which is almost exactly double the Leslie's result, and totally off the charts in terms of what the published 'acceptable' ranges are. Indeed, even at 649, the Leslie's automated 'recommendation' was to drain 1/3 of the pool water and replenish. For this one, while my CSI is fine, I am concerned at how high the level is from a long-term standpoint and would really appreciate input here.
Interestingly, the salt result I obtained matches the readout from the generator itself. I had doubted its accuracy (based also on comments read here saying that the system readouts are generally inaccurate) and assumed that Leslie's was right, but now it seems it was Leslie's is actually the outlier here. I assume that high salt levels can be brought down just through the passage of time and salt being used up by the SWG?
I have recorded all these into Pool Math (subscription purchased), and it is recommending adding:
4lbs 11oz of dry stabilizer to increase CYA to 50 (TFP target 70-80 but want to start low for fear of overshooting)
22lbs of borax (+ acid to maintain pH) to increase BOR to 20 (TFP target 30-50 but again wanting to undershoot to start)
Replacing 66% of water to reduce CH.
The pH today was just under the recommended 7.6-7.8, but I assume will naturally drift up over time like it does every week, so I will ignore the recommended 1lb borax to increase pH.
OK - so reading back that's a lot of information, but hopefully there are some useful nuggets in there. Any advice anybody can offer in terms of prioritizing any necessary changes would be fantastic.. Right now the pool looks incredible, so I don't want to tinker unnecessarily just for the sake of hitting some magical numbers, however the TFP recommended levels presumably exist for a reason, so moving towards them (in 2 batches perhaps to make sure I don't overshoot) would be my goal if the advice here is to do it. Advice on the timing would also be appreciated - I assume I can't just dump everything - acid, borax and CYA - into the pool all in one go, so which to start with etc. would be amazing. And that's ignoring the elephant in the room which is the really really high CH test result. Your thoughts on that one?
Thank you all again for your time looking out for us newbies! I really, really appreciate it!
Ben
First of all, obligatory comment to say what an awesome community this looks to be. The information, guidance and 'keep it simple' approach are all fantastic and right up my street.
So, my wife and I just bought a house that has a pool, and a really very nice one at that. We're in San Jose, CA. The pool is a gunite salt pool, approximately 20,000 gallons (based on squared off actual width/length measurements we took, and average depths taken at either end and the middle).



The pool guys say it's "their favorite pool on their route" and has always only required minimal maintenance from them, which I'm sure they say to all their owners, but who knows. With the exception of some tree fluff falling to the surface each day [probably coming to another thread in the near future - how to really accelerate the skimmer to pick up this stuff), the water is absolutely crystal clear (my frame of reference is that with still water I can clearly see the main drain 8ft down in the deep end, the textured surface, and the vacuum - would pictures help here or does that sound reasonable?).
So far, the only thing I have changed from what we inherited is I changed the timer to run the pump on low power from 9am to 6pm (with 30 minutes initial full power) to keep up chlorine production throughout the day when the sun is out, and swimming happens. The previous owners had been running the pump 4-6..30am and 6.30-9.30pm (and over half at full speed) which I thought strange given swimming and chlorine consumption happens in the daytime), and vacuum for 30 minutes each day 8.30-9am. The SWG (a Nature2 Fusion Soft) is currently set to 50%.
The day we picked up the keys I took a sample of water to the nearby Leslie's, and got these results. The water sample was taken at about midday:
FC 0.9
pH 8.4
TA 98
CH 649
CYA 24
Salt 2960
Phosphates high but who cares!
We are keeping the previous owners' pool service guys going for a month or two while I get used to things. They come weekly and have been adding acid and top-up liquid chlorine as needed based on that morning's results. They're only monitoring for pH and chlorine. I asked and sadly they have not heard of this site, although they did at least point out from the Leslie's results that the CYA could come up (but they didn't actually do it), and the phosphates could be ignored. Their methodology is entirely based on experience and feel. They also thought it was a 30K gallon pool so in a way I'm glad they weren't calculating dosages!
Last week, they recorded FC 5 and pH 8.2, and asked me to turn down the SWG from 100% to 50%.
They came again yesterday, and their test results taken at were 8am on 8/4 were:
FC 1
pH 8.2
They added liquid chlorine and acid.
Being the intrepid DIYer that I am, and based on the glowing recommendations on this forum, I acquired a TF-100 kit to get a more complete picture of the water chemistry. I also bought the salt and borates tests. The kit arrived today and I did some evening testing right before sunset:
Test taken at 7.30pm on 8/5:
FC 5.0 (both FAS-DPD and color swatch - by the way why do the instructions say the water will turn 'completely clear'? Mine went milky white in a single transition at 10 drops - 5 FC - and stayed there but never went actually transparent / clear as I would interpret those words)
CC 0
pH 7.5
CH 1250
CYA 22 (20 if I round off per the instructions)
Salt 3900
Borates 5 (not 0 but definitely not 10 from the swatch)
The two results that jump out at me are that the salt level, being 1000ppm higher than the Leslie's test result, and the CH which is almost exactly double the Leslie's result, and totally off the charts in terms of what the published 'acceptable' ranges are. Indeed, even at 649, the Leslie's automated 'recommendation' was to drain 1/3 of the pool water and replenish. For this one, while my CSI is fine, I am concerned at how high the level is from a long-term standpoint and would really appreciate input here.
Interestingly, the salt result I obtained matches the readout from the generator itself. I had doubted its accuracy (based also on comments read here saying that the system readouts are generally inaccurate) and assumed that Leslie's was right, but now it seems it was Leslie's is actually the outlier here. I assume that high salt levels can be brought down just through the passage of time and salt being used up by the SWG?
I have recorded all these into Pool Math (subscription purchased), and it is recommending adding:
4lbs 11oz of dry stabilizer to increase CYA to 50 (TFP target 70-80 but want to start low for fear of overshooting)
22lbs of borax (+ acid to maintain pH) to increase BOR to 20 (TFP target 30-50 but again wanting to undershoot to start)
Replacing 66% of water to reduce CH.
The pH today was just under the recommended 7.6-7.8, but I assume will naturally drift up over time like it does every week, so I will ignore the recommended 1lb borax to increase pH.
OK - so reading back that's a lot of information, but hopefully there are some useful nuggets in there. Any advice anybody can offer in terms of prioritizing any necessary changes would be fantastic.. Right now the pool looks incredible, so I don't want to tinker unnecessarily just for the sake of hitting some magical numbers, however the TFP recommended levels presumably exist for a reason, so moving towards them (in 2 batches perhaps to make sure I don't overshoot) would be my goal if the advice here is to do it. Advice on the timing would also be appreciated - I assume I can't just dump everything - acid, borax and CYA - into the pool all in one go, so which to start with etc. would be amazing. And that's ignoring the elephant in the room which is the really really high CH test result. Your thoughts on that one?
Thank you all again for your time looking out for us newbies! I really, really appreciate it!
Ben
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