I am selling a Katadyn PowerSurvivor 80E /12V (modular) - One of the most efficient electric desalinators/Water Purifiers including an Extended Cruise Kit and extended 2-year warranty. We bought it Nov 2007 and it was installed but it was never used. It comes with every original part. Asking Price: $4,300.
Technology Reverse Osmosis: Output (+/- 15%) 3 gal/h - 12.9 l/h
Salt rejection (avarage) 98.4% (min. 96%)
Power requirements: 12-volts DC/8 amps, 24-volts DC/5 amps
Weight: 34 lbs/15.4 kg
Dimensions: 6 x 16 x 14 "/15.2 x 40.64 x 35.6 cm
Plus Extended Cruise Kit:
8 x 30 Micron Prefilters
4 Alkaline Membrane Cleaner,
2 Biocide Membrane Preservatives,
2 Acid Membrane Cleaners,
1 Repair Seal Kit,
1 Dist Water Tester
I am not exactly sure as I am not familiar with the Spectra Watermaker. I assume you are talking about the Ventura 150. I couldn't find any exact comparisons online but I think the Ventura makes around 6 gallons per hour and the PowerSurvivor 3.4 gallons. The Ventura is more expensive as well.