Charcoal Water Purifier

Browsing through the recipes.json I noticed that the charcoal water purifier crafting recipe doesn’t have charcoal in it. Don’t you think it’s weird? Maybe 1 or 2 charcoal should be added.
The link’s here

The charcoal is "r"eloaded into the purifier, like batteries. Only it’s significantly more inefficent than just burning the wood needed to make the charcoal and purifying the water that way.

Hmm, I thought water purifier using charcoal rarely need renewal? I could be wrong though but most of the water purifiers I’ve seen don’t need charcoal replacement, once they exhausted you just discard that purifier and buy a new one.