Didn't say it didn't, it just isn't as concentrated. I didn't read anything about lowering pH, I don't know why they would risk tampering with something like that. But I didn't look very hard either.
The jug thing was in reference to using PRIME, which is more concentrated and would require i think 1-2 drops per gallon of water or something of that nature. Which lasts quite a bit longer.
Sorry, these are just recommendations that GTP keepers use, as they are a bit more sensitive to things like water condition as babies.