"Pure water" from bob's mods has the same texture as "water" when set to custom icon.

You are correct:
Mine vs Bob's.

Not terribly surprising, the source for both is clearly the public domain image of a water molecule from Wikipedia (or at least mine is).

However, there are other options in the mod available for water:

• Icon overlay (overlays this custom icon in the corner over the default icon)
• Text overlay (overlays "H2O" over the default icon)

Do the other options not work for you? Is it a preference thing? That is totally valid if so.

I am completely willing to change the icon if you or anyone else has a good suggestion. But despite what it may seem, I am not a skilled graphic artist, and a suggestion like "do a water bottle icon" won't get the icon changed, I would need at least a good starting point example.

just search up water bottle vector art non copyright on google and i found plenty of images that would fit well