New pool finally in- finished filling and turned on pump last evening at6:30pm- water a little cloudy and a tad greenish, but not bad- that is how it comes out of the faucet here in rural North Texas. So time to add chemicals. Using TA-100 test kit.
Starting water values in the pool before chemicals:
Temp- not sure, but a very pleasant compared to 100 degree air temp.
Started with 2lbs of di-chlor that we had on hand to get the ball rolling. Wanted to shock out the CC's and any algae that might be getting started and get some CYA in the pool.
According to pool calc- 2lbs of di-chlor in a 20,000 gal pool should raise FC by 6.6, raise CYA by 6, lower PH by -0.25, and raise Salt by 5.
Sure enough- the ph and T/A dropped rapidly to 6.8 and 40-50 respectively. The CYA level is still too low to register on the TA-100 test, so cannot confirm that. And the water did get much clearer.
But what confuses me is that FC did not test higher than 4.5 and an hour later was back to 3.5. CC did drop to .5. After a couple hours of testing, it was way late- so we added a 2lb box of baking soda (all we had on hand at the time) and 2 cups of 65% of cal-hypo to the skimmer and went to bed, leaving the pump/filter running.
This morning, under cloudy skies and "only" 90 degree air temps at 10:30AM, my results are:
CC=.5-1 (see below for why I am uncertain about this)
CYA= still not enough to register.
And, the water is cloudy again, but no green tinge.
( It has just rained briefly for the first time since early June (of course ), and now the sun is out, and it it supposed to repeat that cycle all day today, so these numbers will probably change.)
So, what happened. Why did the chlorine not go up to as high as expected?
CC Uncertainty: Also, a little side question about the CC drop test- I add the reagent for that test- 1 drop, and the solution turns clear. That makes my CC=.5. I put down the vial to move on to the TA test, and few minutes later, notice that the Chlorine vial has turned a light pink again. So I add another drop of the reagent, and it turns clear again. So is my CC now 1, or is this a normal thing and I am just supposed to go with my initial 1 drop?