Hi! I'm new to TFP and have been reading for hours over the last week. I have learned so much already and wish I had found this site 7 years ago when my pool was new. I've read through Pool School so I hope I am doing this correctly so as to not make you repeat yourselves.
So, my first concern is black algae. I did the fingernail scrape, and it looks like tiny tiny black spots in the pool (shallow and deep ends) but smudges green on white paper. Over the summer we noticed them and could scrape them off with some effort. Now, months later, although they don't seem to be multiplying, they are still there. I have been a little lax about my water testing so I take the blame for this. My pool looks crystal clear but these little spots are hanging on. I'm running my pump at 60% 5 hours a day right now.
I ordered the Taylor K-2006 after reading your forum and tested the water yesterday. I had a much simpler drop test that needed replacing. I also took a sample to my local pool store, which I do not like going to other than to purchase acid and salt.
Here are the results of my test and theirs:
Taylor , Pool store
FC 6 , 7
CC none, no results shown
Ph 7.8 , 7.8
TA 60 , 80
CH 210 , 250
CYA less then 30, 20
salt SWG green, 3100
I know my CYA is low but I don't know what to do first. I want to get rid of the black algae as efficiently as possible.
Thank you for your help