To me it looks like your plants need a good drink of plain water. Listen to your "gut feelings" on this one. Your intuition is telling you your plants are thirsty, but your head is full of doubts caused by reading too many suggestions or opinions of others. Could this be thee case??
Also, I personally can not recommend 24 hours of light. Believe it or not, but plants do actually need to "sleep". It is part of their genetics. By having 24 hours of light for 7-8 weeks already, I imagine your plants would be really freaking out by now. Your plants will actually perform best/most efficiently with a 18/6 light/dark schedule.
For a more detailed explanation, see the answer I gave on this same topic to SF2000_3x3 for his auto Chem OG and auto Cheese grow.
Hope this helps,.... Organoman.