Nooooooo, never said that. All nutrients are available at 5.8, as they are at 6, and 6.2, and 5.5.
The amount of nutrients that are available changes SLIGHTLY at different ph levels.
Yea but doesn't 6.0-6.5 give slightly better uptake for most of the important nutrients.
6-6.5 gives you better uptake of nitrogen, potassium, sulpher, calcium, iron, and molybdenum.
5.5-6.2ish for phosphorus, boron, copper, zinc.
Manganese is really low below 5.0 lol. Seems like you can't uptake phosphorus past 6.2 but at the same time that guy was saying the Herculean which is mostly bone meal needed high ph.