Question We live on Long Island and have a gunite pool. My husband has maintained the pool for over 38 years with little or no problems. Two years ago we had the pool refurbished including new marble dusting. Since that time we have been having a problem with green algae. My husband thinks it is a problem caused by the marble dust not being properly applied. As soon as he brushes it off, it comes back. Can you give us any suggestions on how to resolve this problem or do we need to have the pool marbled dusted again? Of course, we won't do this until next spring. Any information you can give us would be appreciated. Thank you.
First and foremost you have maintain pool water chemistry.i.e pH and Free chlorine level, if you maintain pH around 7.2 to 7.4 and Chlorine around 2 ppm the problem will be solved.
But what you said is also correct vis-a-vis workmanship of the pool.