Why only 1" hose???
I can understand why any overboard discharge hose from the macerator would be 1", but all tank and Type I MSD inlet hoses are 1.5", and so are are all tank pumpout hoses. If you have a Jabsco toilet, Jabsco offers a choice of 1" or 1.5" discharge fitting...and if you replace the 1" fitting with 1.5", you can eliminate the reducer fitting in the head discharge hose. And btw...if you're gonna replace ANY hoses, replace 'em all. Don't only replace the head discharge hose. If it's permeated, the tank discharge hose is even more likely to be. As for hose quality, the only hose that's proven to be "bullet proof" is SeaLand "OdorSafe," which is only available in 1.5"...and that's only because it has an impermeable "skin" bonded to the outside of it. Testimonials notwithstanding, it's just about impossible to predict how long it takes any other hose to permeate. It all depends upon the installation...whether there are low places where waste can sit and ferment or not. The same brand/type of hose that had been on one of my boats for more than 7 years without a trace of odor began to stink ess than 90 days after I installed a complete new system.