I have been struggling with this issue on my frogbit for a while now and I can't seem to figure out what it is. I thought it was micros related so I switched to @Burr740 micro mix and while my new leaves showed improvement I still see this pattern on old leaves. Which I'm aware usually means a macro nutrient but I didn't start there since it didn't seem obvious what macronutrient it was. I dont dose nitrates but they hover around 7-10 ppm in the water. I use red root floaters to tell me if there is enough nitrogen in the water and they are currently very green. Phosphates I dose 2 ppm weekly and they average 2-3 ppm in the water. Potassium I recently increased to see if I would see improvement but I did not. I am currently dosing 20 ppm potassium through potassium sulfate. Magnesium is currently dosed at 5 ppm weekly. Calcium averages about 20-25 ppm. It leeches from concrete hardscape. KH averages 1.5 - 2. Degassed pH is 7.2. During CO2 injection it is brought down to 6.3. I water change 50% once a week. I am stumped. I have no idea what I'm missing that is causing this. I also see it in some aquatic plants like the ludwigia super red.
