Hello, new here, in central Illinois, been a pool owner for 5 years. Always went to the pool store, bought their products (bioguard) and had them test my water. i have had no issues till opening this year. cloudy water and no answers, so here I am, looking forward to taking control of my pool chemistry. i have a 13,500 galloon steel above ground with vinyl liner. sand filter and pump. also a heat pump heater.