What is The Issue Here?

[Liqurd4tay0z]

Hi all I have been noticing for the past 2 weeks or so that some older leaves have what appears to be rust fungus. Im not quite sure if this is the start of a deficiency of some sort or something worse. I recently transplanted to her final pot because she was rootbound and I am thinking this might be the cause. Since uppotting I haven't noticed it getting worse and there has definitely been a huge increase in growth since. I was thinking a calcium deficiency so I started giving some calmag yesterday and will wait to see how she reacts.

 

[Lime]

Leaf touched soil or edge if container, old leaves die off when not receiving enough light.

If thats the only leaf affected i wouldn't worry about it, rest of plant looks healthy.

 

[Liqurd4tay0z]

Leaf touched soil or edge if container, old leaves die off when not receiving enough light.

If thats the only leaf affected i wouldn't worry about it, rest of plant looks healthy.

It's several leaves probably about 4 or 5 but they are mostly near the bottom and a couple in the middle (older leaf)