Halophila is pale, not bright green.

[eddiesylas]

Is this an iron deficiency?

Across the light spread in the tank there is a distinct gradation in color from light green under the brightest spot to bright green under lighting just outside of the "spot light" radius. But additionally, some of the leaves are also paling to almost clear on various branches.

Nutrients:

PO4 ~ <0.25
NO3 ~ <0.5
Both visible indication API

[Amphiprion]

Originally Posted by eddiesylas

Is this an iron deficiency?

Across the light spread in the tank there is a distinct gradation in color from light green under the brightest spot to bright green under lighting just outside of the "spot light" radius. But additionally, some of the leaves are also paling to almost clear on various branches.

Nutrients:

PO4 ~ <0.25
NO3 ~ <0.5
Both visible indication API

IME, it's like that. I've tried iron and it may help a bit, but some are always a bit pale looking. Doesn't seem to stop it, though. If they are really pale, a little iron may not hurt. The only other time I see this is in very low light areas.

[eddiesylas]

Thanks.
I am going to dose "recommended" amounts twice per week and see what happens.

[Disher]

Make sure you get an iron test kit if you will be dosing iron.

[Amphiprion]

I don't think any available test kits provide a low enough range for iron. Other than that, it is often depleted so quickly in many aquariums that it likely wouldn't make a difference. This may apply even more in systems with a lot of plants and/or algae.

[eddiesylas]

I have read and experienced the same. The indicator I will be looking for is a more saturated looking color in the plants. And even that may not happen.