I have a 6 year old 80 gallon American water heater, looking to check/replace the anode rod for the first time. It currently has a 3/4" aluminum anode rod, 52" length. I need a flexible anode rod, as I have very little clearance to put a new one in. The longest flexible one I found is 44". Can I use a shorter anode rod than what it calls for? Would it simply mean it may corrode faster?