having problems calculating heating cable length/wattage for a 35 gal hex tank. 35g=132 l(35g*3.78l/g) on the documentation(All glass Aquariam co) the measurements for the tank are 23L X 20W X 24W which converts to (1" = 2.54cm) 57.5cm X 50.8cm X 60.96cm Volume = L * W * H =178064 cubic cm (Since 1000cm3 = 1liter) = 178liter 35 gal tank = 132 l or 178l should calculate .2 X 132 or 178