tenner plants

Everything seems okay in here, except I notice a few things. Last week, and the week before (the day I dosed Mg) the plants were pearling. This week, none of that. I'm wondering if I need to add a tiny bit of Mg each week? I have found the water report that lists Ca and Mg from our local water source, and I'm surprised how much it varies per month tested- the ratio Ca:Mg was sometimes 4:1 other times roughly 3:1. I wonder if the plants feel the lack of Mg in months when it is lower... Still somewhat confused on this point, what I should do.

Because I notice that although this anubias looks relatively fine,

the other one has hooked tips. (I do think that anubias on the larger wood piece is going to 'walk' all the way off of it and span the gap. It will be like an anubias bridge. I'm very curious to see how it grows!)

Yet its scion (smaller plant right next to it with the new shoot coming up) doesn't. And the baby plant's leaves are rounder, why is that?

On the other end of the tank, the remaining piece of anubias barteri, still very small, has rounder leaves as well. (It's on the top left of the log, just above the buces). Maybe they just grow more oblong as they mature?

Also this week for the first time my buces in this tank have poor color. Not the new ones I added, or the mature 'selena' on the substrate level, but the 'isabella' ones on the log and the darker one on the stone, have yellowing of the leaf body with darker veins, same symptom my anubias often shows. I am trying to think what I did different the past week, or what is lacking. Could it be iron deficiency? it is a long time since I used root tabs in this tank.

Most everything else in here is looking fine, or just not showing symptoms yet... Lower leaves of ludwigia yellowing and some dropping off, but I always kind of expect that. I had some fun with changing the background last week. Went to the fabric store and picked up half a dozen pieces of different shades, just big enough to cover the back of the larger tank. Whatever one I didn't use for that, could be for the tenner here. Black seems too dramatic:

And blue felt washed out.

In the end I chose to use a dark gray felt.