You might need some GH booster.
With that much light, I would.

CMS is okay, I personally do not like it, I prefer TMG, in about 3-4 months(summer), I'll have the special dry trace blend that's better than anything on the market.

It uses a mix of different chelators similr to that of SeaChem and TMG but for all the trace metals, not just Fe.

General dosing:

After water change: 2-3 teaspoons of GH booster
3x a week starting right after the water change:

1 teaspoon of KNO3
1/4 teaspoon KH2PO4
20 mls of Trace

You might up this a tad as the plant biomass fills in.
Most folks have issues with CO2 from there as EI rules out low and high levels of nutrients.


Regards,
Tom Barr