have got quite a few spots of black algae in the pool, have previously put in 20lt of chlorine but to no effect. I had also put in an a liquid algae killer that the local pool shop gave me. But no joy.
here is the pic of the problem area in pool http://imageshack.us/photo/my-images/81 ... renjy.jpg/
Here is the pool chemistry.
the frequent rain here in Brisbane may have contributed as well.
thanx a lot for your help.