my chairman II arrived sat, electrician coming wed...i am a little confused regarding chemicals for this hot tub...the vision cartridge is replaced every six months..the dealer also told me to drain water every six months...not three...he also told me i didn't need to drain the tub after the first 30 days...plus he said only put maybe a tsp of clorine once a week, and shock with mps once a week...my other question is ..if i decide to drain tub sooner then six months does that mean i have to replace the vision cartridge at that time or can i use the same one...two different salesman in the same showroom had different answers..is there a spokesman for d1 out there that can set me straight ...i will be ready to fill tub on wed...come on d1 reps chime in please!!