I want to install a bathroom w/toilet in the basement. My only option without mass destruction is the saniplus toilet system(very European, BTW) My issue is the P trapp for the shower and how much elevation to the holding tank on the SaniPlus...wondering if the Sanishower eleminates the need to elevate the shower base? Other options could be to lower the holding tank on the Saniplus by about 2"? Any help would be appreciated.