Review on AA GKM9W Internal Aquariums Black by Amber Vue

I had a sudden bloom of algae in a 20 gallon tank. After doing a half water change and changing the filter pads for several days in a row, the algae was still there. I bought this UV pump and it arrived on time. Installed on the day of receipt (10 days ago) and the water was not cleaned at all. The filter is clean, the pump is pumping, the green light on the side of the box is on. That is everything I know. I can't know if the light is on as it's a closed device. I don't know what to do other than change the water and pads. Update: Replaced almost all of the water and replaced my regular pump filter as before. The water is quite clear. The UV pump is still running 24/7. So if algae keeps growing, I know this pump isn't helping. I want to take a before/after photo. Yes, and all this time I turned off the light in my aquarium, and the aquarium is in a fairly dark room.