Time to add CaNO3 and MgSO4 EC reading strangely dropped to 700 plus before slowly rising to 1200. This is unusual. The reading is usually quite immediate. Still some signs of yellowing and burn tips. So time to top up CaNO3 and MgSO4. Added 1L water with 1/2 teaspoon each of CaNO3 and MgSO4 (Epsom salt). EC1210 pH5.87 WT30 Water level: just below mid level.