New grower here. I had a problem with plants leaves being light green / yellow . Ph was on high side I got it to 6.0 now . New growth is nice and green but the older leaves seem to be getting yellower and I seen a couple spots they were a little it was a little dark. Could it possibly be over nutrients? I'm using general hydroponics 3 ports system. I haven't changed the solution in almost a week another thing is my net pot doesn't stay wet I have the nutrients about an inch below the bottom of the pot I have two air stones I'll post pictures of that also. Help is greatly appreciated please keep in mind I am fairly new and I might have made some stupid mistakes but you learn from mistakes right