Originally Posted by kekon
I It usually worked fine for about 2 months but after this time i noticed that many young new leaves became pale and growth was poor. Most plants looked as if they were iron starved so i added high iron doses ending up with over 0.5 ppm Fe in the water column. Such high level of Fe didn't improve anything. I also increased manganese dosage (Mn deficiency may resemble Fe deficiency in some cases) but it was all in vain.
Most articles and literature connected with terrestrial plants say, Mg deficiency appears as yellowing on lower leaves. I can say that in many cases it's not true in planted tanks. As i have written above i experienced Mg deficiency that appeared as yellowing on young leaves.
It's often confused with Fe deficiency.
You are absolutely right! I've passed through everything you describe above, especially with pale Anubias leaf when high light exposed. Congratulation for your such in depth research for this problem. It was very useful for me and probably for others too!