Moved to new home last July. Pool already opened when moved in. No problems until late September until put solar cover on pool. After that, yellowish sand/dust would develop overnight at bottom of pool. I raised chlorine levels, and continued vacuuming, but not successful. Other than the yellowish sand/dust (which I am guessing is mustard algae) on the bottom of the pool, especially in areas where walls meet floor, the water was completely clear and looked clean.
A pool company opened our pool this year (never again). Water cleared up a few days after opening. Since then I have been unable to keep chlorine in the pool (using combo of trichlor and liquid chlorine) and I have been seeing the yellowish sand/dust on the bottom of the pool again. (no luck with vacuuming, etc- just comes back next day).
From my reading, I think I need to SLAM the pool. Just want to make sure that is the correct action before I try.
Readings are at:
PH - 7.2
Clorine been running at under 1 (confirmed by pool store) except after adding large amounts of liquid chlorine (it was 4 today after gallon of 12%)
TA - 100 (pool store analysis said 80)
CYA - 50 (confirmed by pool store analysis)
Am I correct that a SLAM is the only way to get rid of the yellowish sand/dust ?
Should I do further testing before beginning the process ?
Are these test levels acceptable to begin the SLAM process ?
Also, I plan to fully clean the DE filter because it was not done last year and I do not know when the last time it was done, should I clean before or after slam?
Could the solar cover have caused the algae (is there a way to clean?) ?
Thank you in advance