I think excel will help you keep algae away, I would dose it regardless.
Have you thought of using Dry fertilizers? KNo3 and K2Po4 and I think Kh2Po4, you might not need the K since it being dose along with the other two.
You can get 800 g for about 6 bucks and it will literary last a life time with the size tank you have.
I got the HC to turn greener from the extra K I was dosing, the yellow had to be cut off but the new leafs are noticeable greener.