I have a situation similar to Tirebyter's post of 10/8/201. A customer has a glass block shower wall that has leaked along the base and algae has taken hold. I've tried opening the grout line and treating with bleach followed by Wet and Forget before regrouting with siliconized grout caulk. The issue still remains. Does anyone know of a good abatement procedure which does not require removing the wall?

I've had aquariums of different sizes ranging from 5gal - 100gal over the years. About 10 years ago I found a gorgeous custom tank someone had thrown away, it had layers of different color, rock hard algae covering most of it, I tried scraping it, scrubbing it, bleach, soaking it, nothing worked well. A co-worker of mine laughed when I talked about it [his family has a few fishing boats on the coast for generations], he said use vinegar and hot water. Having tried everything else already I gave it a shot and it ate through the algae so well I was able to just wipe it away. To this day I'm still amazed that vinegar did the trick when bleach did nothing. Hope this helps.