Neseasa Golden Not Growing Well

I started this aquarium a month and a half ago. It started out a little rough. none of the plants were growing well. It looked like a micro nutriant deficince so I up the micros(the only thing I changed) and things just got worse.

I halfed my origional micro dose and things got lots better. Now everything is growing well except for the Nesaea golden. The nesaea golden was doing much worse until I lowered the micros.

It never seems to open up and the leaves are long and narrow and it is growing slow. The stem is not pink either.

Dosing daily-
.75ppm Potassium
1ppm Nitrates
.5ppm Phosphates
.25ppm magnisum
0.03ppm Iron/traces

Other specs:
20 gallon long
CO2- 1.5 drop in CO2 on from 9-6
Light- Planted Plus HCL 24/7 on at 8 out of 10 brightness for 3 hours, and full brightness for 3 more hours
Black sand
Weekly 70% water change

Water parameters:
KH 7 but goes up over the week
GH 7 but goes up over the week
ph: 6.3 with co2 to 7.8 without
Nitrates- 2ppm

I'm keeping nitrates under 5ppm to get my rotala rotundifolia more red

Brown Diatoms are going way and the only algae is staghorn because I'm going from 2 water changes a week to 1.

 

I'm pretty sure it was grown submersed.