Hi shanti thanks for lookin in,
fed them low dose of grow and e salt,twice before going in 12/12 they had had just water up to that point and regular pot up's,plants look very healthy now,i thought it may have been heat,i raised the veg light slightly but it didn't improve,but in 12/12 not a single twist on any,they have had just water since,next water they will get a feed,so no prob's with them now,never seen it before.
so it does sound like it was lackin something,like you say,cheers
peace.