Should I worry and if it is the ph what are the best ways to adjust up or down ?
it is not the pH at this point in your grow. All the plant really needs right now is Nitrogen, and N is available to the plant across almost the entire usable range of pH. Also, the ONLY reason we adjust pH is so that chelated nutes (the most common kind) are in the correct range so that they make everything available to the plant. Since you are not yet using nutes, there is no need to worry about pH yet, of your incoming fluids, and certainly not the soil. Soil is adjusted to where it is for a very very good reason and if you mess with it on advice from the internet you are likely to get lost going down that rabbit hole. Adjusting soil pH is a new fad, and one never heard of (unless you were growing orchids that need a very acidic soil) until recent years. You bought good soil... trust it.
i also strongly doubt that you have already depleted this good soil of its initial load of nutrients... maybe in about a month, but not yet. Your plant should be doing a lot better than it is. I think I may have an explanation.
Where did this idea of the rocks on top come from. Were they washed before use, or did a lot of that phosphate dust come along with them into the top of your soil?
We have this thing called Mulder's Chart of nutrient interactions... here it is:
This chart informs us that a lot of phosphate in the system will decrease the plants ability to see Calcium, Potassium and Iron. Since these are needed nutrients, even this early in life, I think the early leaf symptoms point to all three of these deficiencies. Your soil is fortified with N, but will only have trace amounts of these 3 elements. I think based on what we are seeing, that there is now a strong need to feed these plants a good full range nutrient system, adjusted of course for their age. I suggest Fox Farms trio and the solubles to use with this soil and then follow the feeding instructions to the letter.
