I found this site by googling. I am at my whits end. We have a 16,500 gallon in ground pool-chlorine. It is green! We went on vacation and it rained the first day we were gone. 10 days later we returned to the green monster. Almost a month later we are still battling this nightmare.
I’m sure I’m going to forget a few things but here we go. We have used two bottles of algaecide, nothing. We have used a bottle of green to clean. Nothing. We did the slam method-nothing. All the while the numbers have been normal.
We drains the pool last Wednesday due to elevated CYA. Refilled and took a sample. Everything looks good number wise. Still green! We shocked w four bags of shock this an. Maybe lighter but still green. Filters are clean, pressure is good. Brushed the walls continually while draining. Cannot see any visible algae. So tired of throwing money in the green monster. It’s hot and we would like to utilize the pool in this Texas heat!!
I’m sure I’m going to forget a few things but here we go. We have used two bottles of algaecide, nothing. We have used a bottle of green to clean. Nothing. We did the slam method-nothing. All the while the numbers have been normal.
We drains the pool last Wednesday due to elevated CYA. Refilled and took a sample. Everything looks good number wise. Still green! We shocked w four bags of shock this an. Maybe lighter but still green. Filters are clean, pressure is good. Brushed the walls continually while draining. Cannot see any visible algae. So tired of throwing money in the green monster. It’s hot and we would like to utilize the pool in this Texas heat!!
Everything added above (algaecides, shock, etc) will do nothing to help. In fact, those might make things worse. When you get algae, you need to follow the 
