@debono, not too sure on your opinion on "The total volume of water is 300% of the original".
Endless seems to got the wording right for this sentence, as 300 litres is 300% of 100 litres, meaning it is 3 times the original. 300% simply equates to multiply by 3. Just like if you say the volume now is 50% of the original, that will mean half of the original. The key word here is "OF".
However, IMO, when you use "up", that will mean increase by. So, IMO, Endless is using the "up" word incorrectly.
