FFO PH help

May 17, 2021
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New grower and I have a question. Growing in fox farm ocean using tap water. PH going in is 7.2. Now when I do a runoff I get 5.0. I don't understand why.
When you water a pot, the water combines with CO2 to make a weak acid called carbonic acid. The weak carbonic acid ionizes and releases hydrogen and bicarbonate. The hydrogen ions cause soil particles to release calcium ions from soil particles.
As the amount of hydrogen ions in the soil increases the soil pH decreases thus becoming more acidic.
In your case, it could be the FF Ocean may have been acidic to start with and the water's pH is overwhelmed by the soil's pH.
Also with the smaller the amount of soil the less buffering of carbonic acid happens.
If you have some leftover FF Ocean you could put a tablespoon of the soil in 2 tablespoons pH neutral water. Bottled water such as Evian or Fiji have a pH of 7.0. Swirl it around and check the pH. Some cheaper bottled water such as Deer Park has a pH of 5.5.
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