First year: algae that came back in a few days, cyanuric acid crazy high, dark spots/streaks on the plaster surface, chlorine that would disappear in a day, and a $20 test kit. At the end of the year I had a 'pro' drain the water and clean the surfaces with muriatic acid. Results were way better than I expected (the dark stuff was horrible and took extra effort and acid to get it gone). Looked great all winter. I want to keep it that way without paying others to do the work that is necessary. I just ordered a TF-Pro test kit and waiting for it to arrive. Took the water to L's and it was mostly good but over 3000 score on phosphates. Worked on that and got it down to 174 and am doing one more treatment today to get it lower. Cyanuric acid is at 88 though that appears to be acceptable (thought I saw somewhere range was 0-30 not 0-100). I am becoming convinced by my googling that using chlorine tabs may be causing the CYA reading to move higher? Clorox bleach at $5/gal, or pool formulated liquid chlorine from HD at $15/gal? Anyway, happy swimming!