Trying to clean in ground pool. My pool is 15000 gallons need to know what to do pool is green with tad polls. had water tested at pool company results as follow: chlorine 0, free chlorine 0, ph. 8.0 ,total alkalinity 100ppm , calcium hardness 275ppm ,stabilizer 40ppm , dissolved solids 1000ppm , langerlierindex 0.5 ,Extensive Mustard Algae