1. Are you shaking the bottle just before you open it?
2. Did you ever get a test kit and confirm you PPM?
3. How long do you let it brew?
4. Do you cool it while brewing?
(1) It's best to vigorously shake the bottle for 30 seconds, and then let it rest for 10 or 20 minutes, otherwise like a bottle of Coca Cola, it will fizz a lot on opening, and then you lose some of your hydrogen gas.
(2) I did better than that: I devised my own method to directly measure the amount of hydrogen gas dissolved in the water, which I suspect is a more accurate way of measuring ppm. Using this method, I found that I was getting 5 ppm H2 concentrations in my hydrogen rich water, when using 3 grams of citric acid and some magnesium. 3 grams of citric acid will produce an internal pressure in a 1 liter plastic soda bottle of around 6 or 7 atmospheres. You can get a higher ppm if you increase the amount of citric acid, which in turn will increase the pressure. But note that these soda plastic bottles will burst at around 12 atmospheres, so you do not really want to go much higher than 7 atmospheres.
If you want to measure the ppm using my method, that method is described in this post. The image in that post has been lost, but the image was of a plastic hypodermic syringe (60 ml capacity recommended) glued onto a small hole in the bottle top, or attached to the hole in the bottle top by a short length of plastic tubing, so that gas can pass from the bottle into the syringe. It is very cheap and quite easy to make this ppm measuring device (a 60 ml hypodermic syringe only costs about $3).
So once your bottle is fully brewed and you have shaken it vigorously, and waited 20 minutes, you then open the bottle, and screw on this bottle top with the hypodermic syringe attached. Then you let the bottle stand for 8 hours or so, during which time the H2 gas will escape from the water and collect in the hypodermic syringe. So after 8 hours, you look at how many ml of H2 gas you have collected in your syringe.
Then your ppm is simply given by this formula:
H2 Concentration in ppm = V / (12 x B) + 1.57
Where:
B = volume of the bottle of hydrogen rich water in liters
V = volume of the H2 gas collected in the syringe in ml
(3) Just until the H2 bubbles from the test tube stop, which is usually after around 45 minutes with a magnesium rod, but is faster if I use magnesium pellets, as with pellets the whole reaction is faster.
(4) No.
Edited by Hip, 04 September 2019 - 10:53 PM.