Black algae problem. Help

[chrismassod]

I have black algae growing on my pebble tec and the tile and the white floats connected to my pool sweep.
My readings are TC 9.5ppm
TA 100
CH 40
CYA 100

Water is clear, no smell. I initially had it in a few spots. I put black algae killer in it over a month and scrubbed the 10 spots i could see it for over hour off and on. I thought it was gone but now I'm noticing it all over probably 200 spots all over. Too much to scrub off. I'm thinking I need to drain pool and have someone come in with acid and scrub off. Help

 

[Butterfly]

What test kit are you using?

CYA tests read 100 and anything higher than 100, as 100 So, you should do the 50/50 dilution test for CYA to confirm that it is 100, or maybe even higher. Regardless, you will need to start with some water replacement to get the CYA down to something reasonable, like 50.

Having black algae does not mean that you have to empty the pool. You can get rid of BA if you follow the SLAM process in Pool School and scrub the BA with an algae brush. You can also rub trichlor tab directly on spots to help kill. The BA has to be scrubbed open (remove outer layer) w/algae brush first to allow the chlorine in for the kill.

Post back with any questions. Someone will be around to help.