I hope this makes it to the right Forum! I have stains on the bottom of my newly re-tiled pool.I have had it drained 3 times. It has been cleaned and in places re-cemented between the tiles. I have been getting lots of useless advice.Everybody says they have never seen this before. Gee,that really helps me. It also doesn't help that i am in Puerto Vallarta,Mexico and the culture here is "different".I am told the stains are due to chlorine powder put directly into the water instead of into the skimmer! How do i remove these stains? Today the floor of the pool was cleaned with Muriatic acid and it did not remove these stains!! I am at my witts end with this problem. I had the pool re-tiled by a professional who showed me other pools he has done with no sign of a similar problem.I just installed the best filter,a new pump but i don't want to fill up this pool again untill these stains are gone,or very close to gone,can anyone help me,i would be eternally grateful,Regards,Martin J.Cavanagh.