Help with Eleocharis Acicularis

I am growing plants with some success when I try. I have recently
redone a 55 gallon aquarium with riccia, eleocharis, and
glossostigmata. I have 20 ppm of co2 on continuous control and 4 X 54W
T% daylight bulbs running 11 hrs/day. I use fluoite laterite clay only
as the substrate and insert a few seachem plant plugs.

For fretilization I try to maintain 5-10 ppm NO3, 20-30 ppm potassium,
and 0.1ppm iron. I dose 0.2 mg/l KH2PO4 1 x per week.

My question is if there a better way to grow eleocharis? Is an enriched
substrate required for this plant?
It has only been in place 1-2 weeks

Drew