I have been chasing low chlorine and black algae in my pool. Not sure why am I constantly dealing with low chlorine and no clue how to kill this black algae.
I maintain the pool weekly and this summer, there was very low to zero chlorine reading during my weekly test. I was previously shocking the pool and using powdered chlorine and tablets weekly. This worked for a year. Then, with the Summer weather and raining, the chlorine level kept reading low and I noticed large black algae splotches on the walls. I think its black algae. So, I switched to liquid chlorine and tablets bc pool store said this was a stronger method. But still, the chlorine level is non-existant after 6 days. Tried to brush the algae, it didnt budge. I bought a black algae product at Pinch a Penny, that was a total waste. I used a Chlorine puck rubbing it directly on a small test area and that works but its a lot of work and Im hesistant bc it might damage the diamond brite? I guess I'll need to get a scuba mask to do it in the deep end and then brush it off after a few hours?
CYA is normal which is strange, I thought this would be due to low CYA. I verified my results at pool store, same thing. They found that all levels were normal, calcium was a slight bit low but they said that was not important for algae. Need help