The latest batch of Water based lubricant is about 60% more concentrated than before.
You can easily fill the bottle again once its half empty with hot water and mix it shake it very well. Sou youre able to get a liter out of the half liter bottles.
If you mix the lube with water to get more we reccommend you to use boiled tapwater or destilled or osmose-technique cleaned water. Because you never know whats inside regular tap water.
And dont mix it with too hot or boiling water, the high temperature might destroy the lidocaine effect and the preservative ingredient.