I'm new to the forum so I hope I'm posting in the right spot...
My pool is cloudy and green with algae. I've been shocking it and it hasn't gotten any better but now that I found this site, I'm going to start the SLAM process once I get a new test kit so I can accurately test my levels. Up until now I've been going to the local pool store to get water tested and each time the levels were "normal" (FC of 3, ph 7.6, TA 70, CYA 40, etc...) but the water was cloudy and green. After shocking, the FC would go up to 10 but not killing the algae.
My question is: Should I consider changing the sand in my filter before SLAM? I read somewhere after googling "algae in pool" that you should change your sand out every 3-5 years. This is the 3rd summer I've been in my house and I never changed it and I have no idea when/if the previous owner changed it. Could having old/bad sand prevent the filter from properly filtering out the algae? I don't want to go through the whole SLAM process if I should first change the sand. How important is it to change out your sand every 3-5 years?
Thanks in advance for any advice