Our swimming pool has tile all around the edges and sometimes it gets algae growing in the seems and, especially in the tile seems that may be slightly cracked. The algae just attaches itself to those areas and really gets a solid foothold and grows out from there. Normal brushing just takes off the surface growth but it leaves the part that is still growing deep into the seem.
When I first bought this house I had a pool technician come over to look everything over and make sure the pool and equipment were up to par. The pool tech saw some of the algae growing in the tile seems then and told that a good way to kill the algae was to take a three inch chlorine tablet and use it like an eraser and literally erase the algae. At the time I wasn't really sure to make of that advice, but this year the algae seemed to really be taking off so I gave it a try. When you do this you really need to be careful that you don't get the chlorine on your body or in your eyes because it is caustic. I put on safety glasses and rubber gloves and went to work "erasing" the algae.
That was about three weeks ago and so far no new algae growths have appeared so it is safe to say that the eraser technique works quite well.
