I had a dull pool half of last season and i just opened it for this season to find a cya of 0. That is probably why my water is dull (y/n?). I need to get CYA UP. I thought i had this stuff (chemistry)down, but after looking into this I am confused, AGAIN. Can i safley add cya to raise it? I've been adding bleach for the past 2 days and it holds over night then i lose a little through out the day. ph is at 7.2 and alk was within range when i tested. Thank YOU!!