GPS, I'm afraid that is incorrect or I am misunderstanding you. Buffers WILL change pH, assuming that the pH isn't too high or too low to overwhelm the buffers. Again, that's why it is important to start with good quality water. The pH of LE's Grow is supposed to be 3.8, but when mixed with 7.0 water it will change the pH to about 5.4-5.8.
Maybe if I try to answer the actual questions, I'd make more sense. Sorry about that.
1) pH buffered means that the
nutrient solution contains an acid and base that work to keep pH within a certain range when small amounts of ions are introduced which would normally cause pH swings. Example: add
nutrients to pure 7.0pH water and you will experience a huge pH swing (the amount of swing depends on the chemical composition of the nutrients). Without buffers, you will need to adjust even if you started with neutral water. Hence the claim that the nutrients are ready for immediate use. Essentially, they made the adjustments for you because they know what effect those nutrients will have on pH. They also used very stable chemicals that will withstand changes (or buffer). I'm also almost positive those statements are disclaimed with the assumption of using neutral water and having a particular water temperature. They are with other manufacturers. I strongly recommend you google "pH" and "pH buffers". pH is arguably the most important thing to understand in hydro, so it would be beneficial to learn more from sources other than forums where you could be steered wrong by just about any of us on accident.
2) Yes.
3) That's the one I answered in my previous post. I just didn't specify. Sorry about that.
Also, I may be wrong, but it appears that you might think the word buffer means "protection from pH". I get that from your asking if the nutrients will still be available even if your
pH meter reads higher. Well, it doesn't. It means some prevention of pH swings and some stabilizing of pH to optimum range in the beginning. In other words, if your solution reads 8.5 that is still bad and the buffers, well, aren't buffering. I hope that helps with some of the confusion.
One last thing: pH swings often mean something. If you are experiencing them daily and drastically (eventually you likely will even if you aren't yet), then it means it is time to change the nutrient solution, you need to check your solution temps, or you may need to start with better water that has lower mineral content.