Mg Deficiency With Super Soft Water?

I have very soft tap water where I live.
I was kinda thinking about dosing Ca and Mg but did not actually dose any.

And this is what happened to my 29 gallon
Crappy pic but I see some new leaves that are pale with veins and old leaves with dark spots.

Mg? Or could be Iron?
I did have NPK and CO2 in excess
I intentionally overdosed macros because I was going to be away for a day or two.
Drop checker is yellow at 4dKH solution and placed in (I think) the worst circulation point. No hardscapes or dense plants yet. 4bps for 8 hrs.
In fact pearling was amazing..
I did go bit too lean on iron (about 0.05ppm I think) and other micros.

Thoughts?