This month, I did about a 30% water drain from my pool. I figured that based on what I figure to be average and how far down I drained the pool. I let everything mix up a bit with the fresh water for several days and then I retested. My goal was to get the salt and cya back to what they should be. Since I didn't build the pool, I can't be certain of the volume. My experience over the past 4 years is that it is somewhere between 32-38000 gallons, based on the amount of chemicals, specifically acid, I have to add and also based on what I can measure in dimensions.
Before the drain, my CH was fairly high (pushing 600) and my salt was a little on the high side as well.
My salt and cya were, of course both very low. Salt was measured 3790 (my Zodiac Clearwater likes 4000 ppm, a little higher than other swg's) and my cya was 35, with a generous eye. It was probably closer to 25. I find this test to be very subjective. I even let the sample warm up to room temperature inside of my house for several hours before testing.
So I tackled salt first, since the pool is still cold and the chlorine demand can't be that high yet. I had 2 50 pound bags of salt laying around and the pool calculator told me to add at least that. I added it and retested a few times over the week. The salt was not raising noticeably! I figured at this point that I was underestimating the volume.
I then got some cya from my hardware store--Pace or HTH brand. I added 12 pounds, which was less than Pool Calculator's recommendations with conservative settings of 32000 and a starting cya of 35 (which I believed to actually be much lower since I could still see a shadow of a dot at 35).
This weekend I replenished my salt strips. The salt measured much LOWER than before (3200), which I figured was more accurate because the old strips were expired. I had my husband add ANOTHER 200 lbs of salt, slightly less than Pool Calculator's recommendation.
The next day (yesterday), I retested everything. I know it is less than a week since I added the cya, but I decided to measure that anyway.
Here are the numbers I got:
FC <.5
CC <.5
(I think the chlorine got used up because I started up my solar last week and there might have been some algae growing in there over the winter?)
ph 7.5-7.6
TA 160 (my fill water is 210, so it went up as expected with the drain and refill)
CH 530 (not as low as I would have liked, but better than before)
CYA 95-100!
Salt 4780!!!
What happened? How could the CYA and salt have risen like this? Should I wait a few more days and retest or tear apart the filter today and clean it thoroughly before any remaining CYA dissolves?
The salt I am not that worried about because it is well within range for the swg. The CYA I'd really prefer to have at around 80. I certainly don't want it any higher than 100! I did not bring the water up to room temp as before, but I thought that would give me a LOW cya reading? I did buy new CYA reagent, but this reading was using the old stuff that I had used for the original tests.
These things are now measuring as if my pool was a much lower volume than I know it to be as a minimum, not to mention the original 100 pound dosage of salt that barely made a dent in the salt reading....
What is going on here? Any ideas?
Before the drain, my CH was fairly high (pushing 600) and my salt was a little on the high side as well.
My salt and cya were, of course both very low. Salt was measured 3790 (my Zodiac Clearwater likes 4000 ppm, a little higher than other swg's) and my cya was 35, with a generous eye. It was probably closer to 25. I find this test to be very subjective. I even let the sample warm up to room temperature inside of my house for several hours before testing.
So I tackled salt first, since the pool is still cold and the chlorine demand can't be that high yet. I had 2 50 pound bags of salt laying around and the pool calculator told me to add at least that. I added it and retested a few times over the week. The salt was not raising noticeably! I figured at this point that I was underestimating the volume.
I then got some cya from my hardware store--Pace or HTH brand. I added 12 pounds, which was less than Pool Calculator's recommendations with conservative settings of 32000 and a starting cya of 35 (which I believed to actually be much lower since I could still see a shadow of a dot at 35).
This weekend I replenished my salt strips. The salt measured much LOWER than before (3200), which I figured was more accurate because the old strips were expired. I had my husband add ANOTHER 200 lbs of salt, slightly less than Pool Calculator's recommendation.
The next day (yesterday), I retested everything. I know it is less than a week since I added the cya, but I decided to measure that anyway.
Here are the numbers I got:
FC <.5
CC <.5
(I think the chlorine got used up because I started up my solar last week and there might have been some algae growing in there over the winter?)
ph 7.5-7.6
TA 160 (my fill water is 210, so it went up as expected with the drain and refill)
CH 530 (not as low as I would have liked, but better than before)
CYA 95-100!
Salt 4780!!!
What happened? How could the CYA and salt have risen like this? Should I wait a few more days and retest or tear apart the filter today and clean it thoroughly before any remaining CYA dissolves?
The salt I am not that worried about because it is well within range for the swg. The CYA I'd really prefer to have at around 80. I certainly don't want it any higher than 100! I did not bring the water up to room temp as before, but I thought that would give me a LOW cya reading? I did buy new CYA reagent, but this reading was using the old stuff that I had used for the original tests.
These things are now measuring as if my pool was a much lower volume than I know it to be as a minimum, not to mention the original 100 pound dosage of salt that barely made a dent in the salt reading....
What is going on here? Any ideas?
