The degree ofacidity oralkalinity of a solution plays an important role in the solubility of mineral salts and their absorption by the plant. However, there is no ideal pH level: a high level favors cation absorption and a low level favors anion absorption. Every decision is therefore a compromise. Moreover, not everyone is of the same opinion: some researchers see no difference between levels ranging from 4.9 to 6.8! Others are much more fussy and adapt their levels to each plant. It is generally recommended to stay between 5.5 and 6.5. Here we prefer to stay in the lower range, and fluctuate carefully between 5.5 and 6.2.