I am a 30 yr pool owner. 18x36 inground. The last 10 years I just feel that my pool supplier is taking advantage of a loyal customer that never asked questions.This year my son told me to go online and see what the heck is going on!!!I just spent over $250 on Biogaurd 73 because I was told I have no free chlorine. I tested it this morning and still nothing.I live in NW Indiana so I just opened the pool. I have had locked chlorine before but NEVER this extreme or was told to use this much chemical.I saw your website and figured I would give my call for help. I feel i am getting bad information and being taken advantage of.