Leaves that are pale or yellow usually signals an iron deficiency. Yellow leaves can also (more rarely) signal a nitrate deficiency. Pinholes in (otherwise healthy/green) leaves usually signals a potassium deficiency.
It looks to me like your iron and potassium, and possibly your nitrate, levels are all too low.
If your tank is relatively small, and you want to take the most convenient (though more expensive) path, you can buy all the ferts you need in liquid form made by Seachem, which sells various solutions in 100 ml and 250 ml bottles. You might want to consider first trying a regular (twice a week) dosing of
Seachem Flourish, which has iron and potassium in it, as well as a bunch of other nutrients. If you do that for a month or so and don't see enough results, then you may have to dose more strongly with the specific two nutrients you need in concentrated form, using
Flourish Iron and
Flourish Potassium.
If you have a very large tank, or you would simply rather take the cheaper option (though one that is more work), you can buy fertilizers in bulk in solid (powder) form that you have to weigh out using a very small scale and mix your own solutions. The source of these that has been most recommended to me is
Rex Grigg. I've never ordered from that site myself so I can't say much more about them.
As for nitrates, presuming you have a decent number of fish in the tank, the best way to raise nitrate levels is to do water changes less often! General suggested ranges for nitrates in a planted tank range from 5-30 ppm, depending upon how heavily your tank is planted and how high your light level is. Very high light with lots of plants and CO2, you want closer to 30 ppm nitrates. Lower light, no CO2, maybe aim for 10 ppm.
I'm far from an expert when it comes to planted tanks, so perhaps others will jump in here with more advice.
