Anode rod height, how accurate do you need to be?

[Bob from accounting]

I am planning on doing an annual replacement of my anode rode, little bit of that sulfur smell and sounds like popcorn inside the tank. Sediment needs to be flushed.
Last Jan I swapped out the rod and flushed it. It is only 4 years old with a one year anode rod. About 10 grains of hardness in our water.

Is there any resource that identifies the length of the rod you need as I forgot which one I bought last year. All the manual has is a diagram that shows the length at 58.5 inches then it also has an area which looks like it is the gas chamber which is 14 inched high. So I am mathematically concluding there is about 44" so a rod that is 44". I see I can get one that is 42" as an alternative. Does it matter? Should I be concerned if the rod touches the bottom of the tank by a few cms? Possible I have 1/2" clearance. I hate guessing. Also last time I had to cut a segment out of the rod as it was too long this time I would like to get it much closer. This leads me to believe the last one I bought as suggested by the manual was 52" which was too long. Also, this is a segmented rod due to no overhead space.
Curious if you have a go to place that identifies the correct length for a Rheem PROG40-38U RH62 EC1. Of course when I search it give me back a 52" rod which I know is wrong. I think?
Here is the link that has the manual and specs which I was striking out on.

 

[Reach4]

I would consider shoving a tape measure down the hole.

You can saw sacrificial anodes shorter.

 

[Sponsor]

 

[Bob from accounting]

I want to order it before opening up the tank. So going to stick with the manual for now, but that is a great idea. I have already sawed it down in the past, going to skip that this time, my bet is that the correct length of the rod is listed somewhere or possibly someone with experience on these WHs knows? My guess was 44" but maybe the rod will touch the bottom with out me knowing? So maybe I buy the 42" version?

 

[TheOverThinker]

I want to order it before opening up the tank. So going to stick with the manual for now, but that is a great idea. I have already sawed it down in the past, going to skip that this time, my bet is that the correct length of the rod is listed somewhere or possibly someone with experience on these WHs knows? My guess was 44" but maybe the rod will touch the bottom with out me knowing? So maybe I buy the 42" version?

The electric ones are just 1-2 feet long, so that's an option for any tank.

 

[Jadnashua]

The longer the anode rod (not a powered one), the more volume it has, the longer it will last.

Some manufacturers actually install two anode rods in their tanks that have a longer warranty.

 

[TheOverThinker]

The longer the anode rod (not a powered one), the more volume it has, the longer it will last.

Some manufacturers actually install two anode rods in their tanks that have a longer warranty.

Does anyone offer a supplemental stubby short anode rod, for cases where
the anode can't be removed from the original spot? Such an anode might go int the drain port,
with some sort of valve...