Never use toilet bowl cleaners in tank (2000 flushes, vanish, blue water cleaners) . As it will damage your rubber components and void the manufactures warranty.
Hard water can cause scale to form inside of pipes and appliances. The manufacturer recommends that you flush your water heater at least once a year to reduce sediment, run more efficiently and prolong its life. It also reduces the soaps ability to lather and dry your skin.
Soft water which basically removes the calcium and magnesium ions in the water and replaces it with sodium ions. It also decreases your detergent usage up to 70%, increases your clothing and linen longetivity, produces whiter whites, increases water heater efficiency up to 30%, elimnates spots and streaks on fixtures, improve water pressure and flow rates and eliminate hard water maintenance issues.