Never really heard that. That's the same story people say when they talk about quality at the big box stores isn't the same but it all comes off the same production line. For the 12 year, I've always heard that it's either two rods or a thicker rod to make it last those 12 years. Tank itself might be the same and maybe the parts are the same.I was told by several people in the plumbing industry that there's no difference in the internal tank between a 5 year or 12 year tank. You get more insulation making the tank look wider, a little faster recovery time(burner) and the additional warranty coverage. Their lifespans are basically the same.
I got these anode rods that are .9 inches thick. They sell thinner ones, as thin as 3/8 so the thinner the rod, the earlier the tank goes.
SP11526C - Rheem SP11526C - .900 x 44-3/8" Magnesium R-Tech Anode Rod
Rheem SP11526C - .900 x 44-3/8" Magnesium R-Tech Anode Rod - <b>Features:</b> <ul><li>Anodic Material: Magnesium <li>Total Length (in.): 44-3/8 <li>Rod Diameter (in.): 0.900 <li>Hex Head Size (in.): 1-1/16 <li>Thread Size - NPT (in.): 3/4 </ul>
www.supplyhouse.com
I just use a sawsall to cut it if it's too long. They charge more for shorter, thinner rods.