a715a371_on__Hardside_Softside_Mattress__0
[1] d [2] c [3] Hardside waterbeds are usually heated (at least in the winter) to prevent an uncomfortably cold sleep surface. Softside waterbeds are sometimes not heated or require less heating. Heating water takes significant energy and will result in somewhat higher electricity costs. [0] 
Energy use / cost
Unbiased Waterbed Reviews and Ratings 2014 : Complaints, Advantages, Disadvantages and Comparison: Hardside Softside Mattress
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