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It wouldn’t surprise me. The e-series has been around for awhile and in my opinion needs a refresh. It looks like the new Celebrity Elite series is going to be the replacement. Unfortunately though, I don’t have inside information to confirm. Parts will still be available and Marquis is a reputable company so I wouldn’t be worried about it and I wouldn’t let that deter me if I was looking at an e-series.
ConstantClean is the name for the Marquis high-flow filtration system, which will come on throughout the day automatically and filter approximately 24,000 gallons per day. There is also an automatic clean-up cycle called SmartClean that will filter the water automatically after each use. All models and series have this filtration.ConstantClean Plus is the addition of ozone and the SpaFrog Inline cartridge system. The ozone helps to limit chemicals and I’m a big fan of the SpaForg Inline system which uses minerals (silver chloride) and a Bromine or SmartChlor cartridge to maintain the water. In my tub at home I have this system and I am only changing a cartridge and sprinkling in a non-chlorine shock once a month. No daily or weekly maintenance for me.
It will work fine without the ozone. I would still recommend having the SpaFrog Inline cartridge system added. Ozone can always be added down the road, but the SpaFrog Inline system has to be added when the spa is being built at the factory (it can't be installed at a later point).