Hi remi96,
I will try to shine some lite on your questions.
First you need to understand that testing your urine and saliva are just tools to use to start seeing and understanding deeper ideas about how the body works!
Then one needs to begin to understand why a test is up or down, as you are now questioning!
Things are not what they might seem to be on the surface, and generally the truths are just opposite as one would first think!
With that said, let us consider what you have asked to understand.
Does water effect the readings? Yes it does!
Water in it's self is acid forming! It carries much Hydrogen with it , which causes acid formation, this is why one may drink much water and stop the problem of constipation, if a person has constipation!
Just one or two days of testing will tell little about a person , and so more data is better to have to make choices about ones condition, overall!
But if one test very acid in the morn before any food or drink, you may know there are problems!!
If a person is on a high protein diet, this may cover up a lack of Alkaline Minerals to begin with, for a short time, so one needs to figure out what is causing the test to be what it is!
If the urine is acid, below 7pH the first thing in the morn, and the more below 7pH , like if it is down below 6pH and below this, then one does not have enough Alkaline Mineral reserves to neutralize the excess body acids and over time these acids will eat away the body's bone structure and do more harm to the body!
These acids then will start to destroy the Kidneys and Liver and all the other organs which are trying to help protect the body from Sickness And Disease!
Because these organs are trying to remove these Toxins from the body, and if there is not enough Alkaline Minerals to keep these Toxins neutralized, then these organs have to deal with these excess acids as they try to protect the body from them, so it becomes a Deadly cycle of Life and Death for these organs to play!
How does water and added liquid minerals effect the pH? "IF" the Liquid Minerals are highly Alkalizing and this is added to the water in enough quanitly, then this will help the body recieve more of an Alkalizing effect, and help the body overcome it's problem of too much acids!
Now this statement needs to be qualified about the Liquid Minerals and if they are highly Alkalizing, as to the effect they will impart to the body!
This statement is stated as to taking into consideration that the Liquid Minerals are of the proper kind so as to provide the needed Electrical Energy Frequencies needed by the body and the body's organs!!
For if the liguid minerals are not of the kind which the body needs, then the long term condition of keeping the body Healthy or helping the body to recover may not then come about and the person may stay sick or get sick!!
For it all brings us back to the idea which I mentioned in the begining , as to the Fact that not all is as it may seem at first glance!!
For example, "IF" the body is short of the Electrical Energy Released from Calcium, and you take Baking Soda, the Baking Soda may temporarily raise your pH , but in the end the body may stay sick or get sicker!!
This is why it is better to learn to eat whole fresh fruits and vegetables which are grown in your climate and season, for these will provide your with the best balance of Alkaline Minerals for your body to get Healthy or to stay Healthy!
And just use the pH test to help you learn and guide you along the paths of better Health!
Smile Tis your choice.