Just got a hot tub. It's used, a year old. The previous owners used bromine. We choose to use chlorine. filled it up 3 days ago. Got a few things at the spa place, not very helpful with what I needed to know I felt. Anyway, They sold me, chlorinating sanitizer, nature 2 cartridge and a film reducer. I checked the water, ph was way high and chlorine was way low. nature 2 cartridge instructions said not to put it in til readings were right. so, i added ph decreaser as recommended and then a couple hours later, I added chlorine as recommended. it was little better reading that night. Next day, they were both off again, again, did this same thing. Third day, same thing, but this time the whole thing went crazy and it turned light green and very very foamy and funky smell! So we drained it. I can't seem to get anyone to tell me what to do. I need help!
The filters in it were the previous owners and they had used them for about 2 weeks. She said they were new, could this have caused my problems?