Powders Increase Neutral Damage

More or less the title, I'm curious how this works!

I was reading the powder wiki to refamiliarize myself, and going over the armor passives.
For example, with the water "Concentration" effect. It says, "gives up to 5% additional Water damage per mana point used". Currently, I'm running around with a Pure build as a mage, that focuses primarily on neutral damage through the raw spell identification.

Let's say, hypothetically, I'm currently dealing 1000 neutral damage and 100 water damage with each meteor. Does the concentration effect increase my water damage by 5%, to make me deal 105 water damage and 1000 neutral? Or, does it increase my total damage by 5% AS bonus water damage, to deal 1000 neutral, 100 water and a bonus 55 water damage?

 

I might be wrong but I THINK this is how it works:

It increases your total BASE damage by 5% per mana used. So if you're wearing armor and/or using a weapon that gives you + neutral spell damage, that won't be taken into account. So lets say your base spell damage is 100 and you have armor that increases it by 200. It wouldn't be +5% of 300, it would be +5% of 100.