Thanks for the reply Zapins!
Couple of things. Are you using Aquasoil? I think I see it in the last picture but not sure.
If you are using it then you really don't need to be dosing the water column with ferts except GH booster and potassium.
Yep Aquasoil. I'm willing to consider going back to just the GH and K, but in the tank's early days - say 6mo in. I had lots of problems with yellowing leaves on the HC, very sad looking didiplis diandra and lots of filamentous and GSA. The GSA subsided once I started dosing my phosphates above 3ppm and the tank has been free off any filamentous algae since I started lightly dosing nitrogen. Causation doesn't necessarily equal correlation here, but adding N/P did seem to help my situation.
The tank is about a year and a half in now and has seen a couple rescapes using the same aquasoil with some toping off. Just fyi.
How sure are you that the N level is 10-20 at all times? I see older leaves have small holes in them on the Rotalas, and smaller new growth which looks like typical nitrogen deficiency.
Well all times is probably generous. I usually test a couple times a week, less if things simply look healthy, and while I know test kits can lie the N is usually around 5ppm after my weekly water change and up to about 20 by end of the week.
Also, do you know what the Ca:Mg ratio is in your tank right now?
No clue. I'll have to pick up a calcium test kit before I can report on that one. Pretty much relying on the GH booster to have proper ratios at this point.
1/64th CSM / day is very high, you are adding 0.12 ppm iron every day from CSM + B, or 0.84 ppm per week Iron. This may not be the cause of your current issue but it is definitely high and could be a problem later since many micros are toxic in tiny amounts.
I'll cut this back by half.