Is this chlorosis?

Hey, That plant is looking okay imo. I notice the slight chlorosis you mention, but I wouldnt be too worried. The chlorosis on the leaves themselves indicate the beginning of a magnesium deficiency. Still very mild at the point of taking the picture, but if those spots get worse I would look into supplementing magnesium. If you're not giving them a cal-mag solution, this would be where I start. Cheers,

Oh, yes, that white thing is not what worries me, it is the interveinal yellowing

No, that's a spot from water drying up leaving any residual salts on the leaf.