Ok, looking at that water and the fact you have passed so quickly I'm going to guess you will be passing
Overnight Chlorine Loss Test. Just a Science "tidbit". The half life of chlorine when exposed to the UV rays of teh sun is right around 50 minutes. So, the vast majority of your loss right now is to the UV rays of the sun.
Once you pass again lets get that CYA in the pool for some "sunscreen". Remember, you add the CYA by using what we call the sock method. Get an old sock (no holes in the toes) and put the measured amount of CYA you need to get to your first target. Tie the sock closed and either suspend it in front of a return (hang it from your brush pole works with something weighted on the deck) OR if it still allows flow thru the skimmer, place the sock in the skimmer. Every 15/20 minutes give the sock a squeeze to speed up the process or just leave it alone, your choice. Please DO NOT follow the directions on the container of CYA to just pour it into the skimmer and don't just toss the sock in the pool as the CYA is acidic and can bleach/stain pool finishes.
The bad news is, once you put the CYA in we automatically assume that it's there and working, so your shock level goes up to 12. While we would like to see it stay at shock as much as possible, the 30 minute testing changes to a two hour cycle during a
SLAM Process. So, I'm going to guess you will get 2 cycles in before the sun sets. Once it sets make sure you add what will bring you to 12. wait somewhere between 30-60 minutes and retest to get a good starting point. If it's not exactly 12, don't add more - just start from where you are. Please be up before the sun is up to test again. while it would be best for the pump to run all night, some have been know to shut it off, but you must start it again 30-60 minutes before you take your morning test sample.
