I would say they know their strain linage. Knowledge of your strains parents and cross polymorphs allows a skilled grower to always make sure that the proper nutrients are available to the plant at the proper time.

If you look at the chart in the grow FAQ section you will see what nutrients are available to the plant at any given Ph level.

That's why you monitor the Ph on your grow in the first place. Don't you monitor that on your grows?
Zandor Reviewed by Zandor on . Greenhouse seed's pH Is there any particular reason Arjan uses pH around 5.5-5.9. I always heard 6.8, but they seem to grow very fine herb heres one of the plants they've grown, but they have many others that are at these slightly acidic pH YouTube - Green House Seed Co El Ni�±o Grow with Italian Subtitles Rating: 5