so now the multiport has to be replaced as well if I do DE- (for an additional $200)! my multiport only is for 1.5" piping as is all the pool piping. the new filter (DE or cartridge) and new tristar pump are both 2" piping. the pool company said they sell 90% cartridge, 10% DE filters and the cartridge filters today are excellent.

ugh....my head is spinning.