Good morning folks, some hostility going on? "maybe buy a good book, so as to avoid bad unfounded advice" LOL
From International Canagraphic mag, IC Mag, The Complete guide to Sick Plants,pH, and Pest troubles!

Nitrogen gets locked out of soil growing at ph levels of 4.0- 5.5.
Nitrogen is absorbed best in soil at a ph level of 6.0-8.0. ( wouldn’t recommend having a ph of over 7.0 in soil) best range to have nitrogen is a ph of
6-7. Anything out of that range will contribute to a nitrogen def.

Hydro and Soil less Mediums
Nitrogen gets locked out of Hydro, Soil less mediums at the levels of 4.5-5.0.
Nitrogen has the best absorption rate at a ph of 5.5 to 8.0
(Wouldn’t recommend having a ph over 6.5 in hydro and soil less mediums.) Best range to have Nitrogen is: 5.0-7.0. Anything out of that range will contribute
to a nitrogen def.

Soil

Phosphorus gets locked out of soil growing at ph levels of 4.0-5.5
Phosphorus is absorbed best in soil at a ph level of 6.0-7.5 (wouldn’t recommend having a ph of over 7.0 in soil) Anything out of the ranges listed will
contribute to a Phosphorus deficiency.
Hydro and Soil less Mediums

Phosphorus gets locked out of Hydro and Soil less Mediums at ph levels of 6.0-8.5.
Phosphorus is absorbed best in Hydro and Soil less Mediums at ph levels of 4.0- 5.8. (Wouldn’t recommend having a ph over 6.5 in hydro and soil less mediums.)
Best range for hydro and soil less mediums is 5.0 to 6.0. Anything out of the ranges listed will contribute to a Phosphorus Deficiency.

Soil

Potassium gets locked out of soil growing at ph levels of 4.0-5.5
Potassium is absorbed best in soil at a ph level of 6.0-9.5. (Wouldn’t recommend having a ph of over 7.0 in soil) anything out of the ranges listed will

Hydro and Soil less Mediums

Potassium gets locked out of Hydro and Soil less Mediums at ph levels of 4.0-4.5, 6.0-6.5.
Potassium is absorbed best in Hydro and Soil less Mediums at ph levels of 4.7-5.3, 6.7-8.5. (Wouldn’t recommend having a ph over 6.5 in hydro and soil less

Remember ProMix is a soiless mix. We learn something new every day.

Adieu