I have been researching on TFP for many years first for a spa, then for the past 3 years since i moved to a house with a pool, and wanted to thank the community you have been very helpful to me so far.
For the past 3 years the pool has been almost no maintenance, been running on the hockey puck chlorine tablets from Costco. when i moved in ~3 years ago i tested and confirmed the cya was too high i think ~110-140 (Was too long ago). about a month ago i was out of town for over a week with the solar cover on, and came back to a swamp as it had run out of chlorine. i shocked and added chlorine, but it didn't kill the algae, so i tested and confirmed my Cyanuric acid was in the ~170-180+ish range diluting 1:2 pool water to purified water.
all tests i ended up doing at the kitchen sink with good lightning and looking into white sink. (it was very hard to get consistent test results for CYA.)
Tests below are from Leslie's, and i have tested myself and they seem to be reasonable.
Leslie tested my Cyanuric acid 3x, first time they said 100, second time i said i got much higher results to which they stated their equipment can't test above 100, and last results was wrong.
the following 2 tests they did dilution of 1:2. their results were then 120 then 140. i don't trust these numbers.
per my many tests and learning how to get a consistent dilution technique, i would say my range was 160 to 200+ but 180 is the most consistent average reading i had, so i am using that as my starting point.
for the most part the above parameters stayed reasonably close. the temperature fluctuates a little but not a whole lot so i would say it was in the 80°F+ range for the whole time.
also because i read that the FC will kill the Cyanuric acid reducer, i elected to do the entire process with no chlorine fully knowing i am turning my pool into a swamp.
below are my results so far, i used 1 8oz. packet. my FC was less than 1 when is started because i didn't wait for the chlorine neutralizer to finish, but there was enough to drop it to zero.
date CYA 1:1
date Cya 2:1
by day 4 the pool was starting to turn green, by day 6 i have a swamp now.
my intention is to get the Cya as low as possible and switch to liquid chlorine with a Stenner pump i have. also after the process is complete it is my intention to shock it to remove the swamp then use the phosphates reducers to reduce the left over phosphates from the swamp i now have, then get my new pool equipment installed.
as for results so far, under best conditions on day 6 have a reduction of 80+ CYA, or under worst conditions a reduction of 40 if you trust Leslie's pools test that i started at 140 which i don't.
i will try to get a sample to them this weekend and post their results.
at least i can get a CYA reading without dilution with my test kit, and i am unclear if i can see a change from day 4-6, i think my technique for dilution 1:2 is very prone to errors.
a few questions i have.
1. do you think i can clean the filter? the swamp is plugging it up, but i fear the bio active is actually in the filter since i added it into the skimmer basket, and by cleaning it i would remove it from the pool?
2. do you think i should use phosfree now? to try to reduce the phosphates or wait until the end?