holes

Some leaves on my Rotalas feature holes/dark spots. Usually on older leaves, but newish growth have them as well, after some time. The issue isn't big, plants appear healthy overall, but still it's the only plant showing any kind of weakness. Water parameters: N: 10-15 P: 1.5 K: 15...

Hi all Would appreciate some help in identifying and dealing with a very recent problem! Have had the planted tank for over a year now, and most of the leaves have developed small holes in them. When looking closer there are many black dots about 0.5mm in diameter. Took a leaf out and under...