I am so happy that your pool is clear of stains!!! Yes, you can raise the water level, and keep the chlorine level high - it will clean the grout, but it will take a while. I love to hear the results of what works and doesn't work. This year I opened my pool to an emerald pond, with strings of green algae My husband wanted to drain and refill, but I knew it could be cleaned up becaue of the information I got reading this forum. That was last Friday evening. I checked ph, and for the first time on opening, my ph was above 8. It is usually below 7. You just never know what a pool will do So I added proteam metal magic - and lots and lots, and lots of bleach. By Sunday the pool was blue - but extremely cloudy. I don't know if it was just dead algae - I think the proteam may have made it cloudy too - it is supposed to turn metals into salts so they can be filtered out (I am not sure that I believe it yet) but there were very small particals that when I vacuumed seemed to go right through the filter. I used some floccuant, and let the water settle overnight. I vacuumed to waste, which made me have to add more (well) water, and I continued to keep my chorine level above 20 with a very low cya. I now have crystal clear water, and no stains - which with such a high level of chlorine for so long was amazing. I did however keep my ph at about 7, with my alkalinity at 100. I wish I would have taken a picture to post what the pool looked like when I opened and how it looked as the bleach cleaned it up. It is hard to believe sometimes, but pictures speak a thousand words. I tested three times a day bringing the level up to 20 each time. Even though I had no combined chlorine showing after three days- the chlorine was being used up overnight, so I continued to keep the level at 20 until it was not going down overnight, which turned out to be 3 days more. And just as a note, I closed my pool the same way as I have the last 4 years, and the last three I opened to almost clear water with a lot of dirt on the bottom. This year we had a lot of rain, my pool actually overflowed, and then a lot of hot sunny days before opening. My guess it that the cover was wet, grew algae and it seeped into the pool and took off - it really ran away with itself So, as I said, you never know exactly what your pool will do, and it is good to share info, so we can help each other.