I have a small button WT that im decreasing now. I had it degrading for about 3 weeks then one day when I changed the water I noticed it had turned green. I don't know if I used to much or if it was the brand of soap. I degraded it with water for a while and it didn't get any better so I have been using water and blue dawn for the last 2 weeks or so, it hasn't gotten any better. What do you think I should do to get it white?