Compare by Plate Size & Power

How many plates?
What’s the wattage?
Flat plates?  Mesh plates?  Holed plates?

Compare by Filtration System

Single?  Dual?  Triple filtration?
How long do the filters last?
How much will it cost to replace the filters?

Compare by Settings & Adjustments

How many preset levels?
Are the presets adjustable?
What pH and ORP will I get?

Compare by Cost & Warranty

How much does each unit cost?
How long is the warranty?
What’s the money-back guaranty period?
And what about restocking fees?