I would beef up the lights. Full blast for more time and thats a lot of water for that light to penetrate and if I'm thinking about the right light. The LED diodes in that system are very small and will have a hard time giving the plants what they need. So Double up or find some bulbs and go hybrid light system like some reefers do. Don't be afraid to blast the tank with light. If you're worried about algae then save your pennies and buy a ton of plants. Load the tank up and scape the plants how you want. That way, you'll be heavily planted and algae won't be a huge issue anymore. Co2 is great but the plants can't convert anything if they light isn't intense enough. Strong Light alone will get plants pearling in Low tech systems. In my dirted tanks, hair grass hauls tail all over the place when the light is bright.