When looking ahead the next big home upgrade, few homeowners consider the toilet. That's a mistake for those with older toilets. Those water hogs account for up to 30% of a household's water usage and can inflate the monthly water bill. Dual-flush toilets cut down on water usage, but if you don't have plans to replace the toilet, a dual flush converter kit is the next best thing. These easy-to-install products replace a normal flapper and chain and can save the average household up to 15,000 gallons per year. The secret is in the handle, which has a button for both light flushes and heavy flushes and signals to the in-tank mechanism how much water to dispense. Available at Amazon; $19.99.