Olga Caussade wrote > I have RO water and it has a pH of 6.5 before storage. > For Paul, no my pH meter do not have a temperature compensation > function.For Peter, I do not have any plants or algae in my water. > The problem is that I grow Phrags and I try to do it between a pH > of 5.5 to 6 > and this fluctuation give me much more work to calibrate my water.
If you have RO water, I would not worry excessively about the pH of the stored water. Pure water has virtually no buffering capacity, so the pH is dependent on whatever substances it comes in contact with. If you are watering with RO water, the pH that your plants experience will be much more dependent on the pH of the potting mix and the pH of any fertilizer you use. Try this experiment. Using a straw, blow air through a sample of your water for a minute or so. Test the pH. Then shake the container vigorously for a minute. Test the pH again. You will probably see a difference. When you breath through the water, CO2 from your breath is absorbed and pH goes down. When you shake the container, the CO2 outgasses and pH goes up. regards, Nick -- Nicholas Plummer [EMAIL PROTECTED]
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