I have dwarf water lettuce that isn’t quite thriving. Some of the leaves turn yellow and slowly disintegrate. According to the aquarium co-op nutrient deficiency graphic, it looks like the issue could be nitrogen deficiency or phosphate deficiency. Nitrates in the tank are generally quite high even without fertilizer (20-40ppm). So that would suggest that the issue is a phosphate deficiency? From the Co-op blog, it says phosphate deficiency is uncommon especially if I don’t have any phosphate absorption and I feed flake food to my fish. In addition, all the my cryptocorynes are doing well, bacopa caroliniana is green but new leaves are tiny, water sprite is turning brown and fading. Does phosphate deficiency make sense in this case?
I did have a lot of brown diatom algae growth that some new otos cleaned up last month. Could the BDA have depleted the phosphates to such a degree?