i really cant tell if you are really serious or not (no offense at all)
i just did a google search and every link i clicked was conflicting with what you said
here is the article i read
Reverse Osmosis/Deionization Systems to Purify Tap Water for Reef Aquaria by Randy Holmes-Farley - Reefkeeping.com
, in short
The pH of the combination of two solutions does not necessarily reflect the average (not even a weighted average) of their two pH values. The final pH of a mixture may actually not even be between the pH’s of the two solutions when combined. Consequently, adding pH 7 pure water to pH 8.2 seawater may not even result in a pH below 8.2, but rather might be higher than 8.2 (for complex reasons relating to the acidity of bicarbonate in seawater vs. freshwater).
a quote from a random forum
"You don't need to adjust the pH of RO
water. Since it has virtually no ions to buffer it, it has no buffering ability itself and will immediately go to the pH of the salt water upon addition to the tank. Not only that, but pH readings of water that is deionized can be inaccurate, so don't even trust the pH measurement of your RO
"Only pure water evaporates at an assumed pH of a neutral 7.0. The incoming RO
water should be very close to tha"
so basically im only putting in what i lose from evaporation, nothing different, essentially
so you see why i have trouble on who to believe, i will side with the majority