It looks like you have your hands full wakasm. Are you able to get the pool to hold any chlorine? With the previous owner using a pool service, I’m really surprised the CYA is zero! Was there a full water change before you bought the house?
Hang the sock from your vac pole so it doesn’t touch the side of the pool. The CYA is acidic and can stain/lighten the wall if it lays against it. If it was me, I would only add enough to get 40 ppm of CYA for now. I would do a SLAM first to make sure the water is clean, and then add the full CYA.
The pic you show in post#18 is a puck floater. You don’t need to use it for now.
In the TF-100 test kit, there are 2 easy to test for chlorine. One is a powder and drop test (FAS-DPD) and is the most accurate and can test up to 50ppm FC & CC. The other uses the drops and comparator block (OTO) and is not as accurate and only tests TC up to 5ppm. You don’t need to do both tests. For now just use the drops and powder test to report FC and CC.
Hang the sock from your vac pole so it doesn’t touch the side of the pool. The CYA is acidic and can stain/lighten the wall if it lays against it. If it was me, I would only add enough to get 40 ppm of CYA for now. I would do a SLAM first to make sure the water is clean, and then add the full CYA.
The pic you show in post#18 is a puck floater. You don’t need to use it for now.
In the TF-100 test kit, there are 2 easy to test for chlorine. One is a powder and drop test (FAS-DPD) and is the most accurate and can test up to 50ppm FC & CC. The other uses the drops and comparator block (OTO) and is not as accurate and only tests TC up to 5ppm. You don’t need to do both tests. For now just use the drops and powder test to report FC and CC.