I grow blueberries, not azaleas. However, both of these shrubs need ericaceous soil to thrive. The soil should have a pH reading between 4.5 and 6 for blueberries. If tap water is used on these shrubs, it should have pH less than 7, which will NOT be the case if your tap water contains dissolved limestone. You can lower soil pH by working in some garden sulfur around the shrub, about one cup per plant. If you have to water by hand, it is best to set up a rain barrel and use this water on azaleas. The leaves on your azalea show sign of chlorosis. The chlorophyll is not developing as it should in the leaves, because the roots are not taking in nutrient from the soil. This happens when soil pH is too high. If you decide to put down granulated soil sulfur, please bear in mind that this application takes about a year to have an effect.

The yellow leaves with green veins is a sign of chlorosis. This is a condition that an acid loving plant gets when grown in alkaline soil. They need more acidity. Powdered sulfur is the best way to increase the acidity. DO NOT use aluminum sulfate. It will kill azaleas.

Here is a link that might be useful: How to grow azaleas and their problems.