What is the output wattage of your light?
Before you invest in more light, you have to find out how much light you currently have. There are many reasons besides insufficient light that plants don't grow, and if plants are unhealthy, algae will take over.
I would suggest that you educate yourself in this wonderful web guidance before making changes.
https://www.advancedplantedtank.com/
If you have questions, it's best to get answers from planted tank dedicated forums such as planted tank net or Aquatic Plant Central
Before you invest in more light, you have to find out how much light you currently have. There are many reasons besides insufficient light that plants don't grow, and if plants are unhealthy, algae will take over.
I would suggest that you educate yourself in this wonderful web guidance before making changes.
https://www.advancedplantedtank.com/
If you have questions, it's best to get answers from planted tank dedicated forums such as planted tank net or Aquatic Plant Central