Hi mate,
Well you really don't need to change anything if you have growth. The dichotomy of an injected tank is all about deciding where biological imperatives end and where ornamental aesthetics begin. I've often implemented strategies in the tank that I knew was good for the tank...until I couldn't stand it anymore because it fell too far outside the boundary of my personal realm of aesthetics. Often the tank just needed to stabilize before it was able to absorb the change I would implement.
More importantly, there should be very little doubt now that excessive light is the root of all evil. Isn't it amazing how 1 WPG in this size tank is OK for these particular plant species and is detrimental to algae?
All the same, you can gingerly add a 28 W burst of energy, say an hour a day for a week, then for 2 hours over a similar period. Just work your way up and observe so that you can see where the trigger point is.
Cheers,