They were healthy green. I measure my ph of my water/tea every time I water. I keep it at 6.3(per my friend who taught me....his look great).... i thought it might be a N deficiency but I have boosted it since and no change, thats why i thought salt buildup.......
Next question. Where on the plants did the yellowing first begin and in what direction did it travel to first?
Some common causes for leaves yellowing starting on the upper portion of plants are:
Fe - IRON (Fe)
Leaves on growing shoots turn pale and veins remain dark green. pH imbalances make iron insoluble.
Mn - MANGANESE (Mn)
Necrotic and yellow spots form on top leaves. Mn deficiency occurs when large amounts of Mg are present in the soil. Foliar feed.
For middle leave a likely cause could be:
Mb - MOLYBDENUM (Mb)
Yellowing of middle leaves. Foliar feed with fertilizer containing Mb.
For older leaves:
N - NITROGEN (N)
Pale plants, red stems, smaller growth. Rapid yellowing of lower leaves progressing up the plant. Add any chemical fertilizer containing N. Treated plants recover in about a week.
Mg - MAGNESIUM (Mg)
Lower leaves yellow and may even turn white while veins remain dark green. Blades die and curl upward.
When you think about where the fading began and how it progressed does any of the above appear to fit the situation?