Review on Get Cleaner & Healthier Water with GRECH CBG-800 5W UV Sterilizer Hang-On Back Filter for 20-50 gallon/211 GPH – Black by Christa Baldwin

I purchased this filter because my 20 gallon aquarium was experiencing a very severe algae bloom. I did 4 water changes in two weeks, 20%, 40%, 50%, 100%. I took the wrong house and plants, cleaned them and left them in the sun for two days. I even got the gravel out with a 100% water change, cleaned it and left it in the sun for two days. I cleaned my old filter 2 times and put a new filter in the filter each time. After I cleaned everything and put it back in the aquarium, the algae bloom started after 5-7 days. Out of frustration, I bought this filter as a last resort. I specifically bought a 20-50 gallon filter because the algae was very bad. And I can say that this filter works! I uploaded five photos to show the changes. The first photo was taken on June 7th when the filter arrived at my house. In the first 4 photos there is paper on the back of the aquarium showing how much the algae are blooming. The second image was taken around the same time on June 8th. The third recording was made around the same time as the others, on June 9th. The fourth picture was taken on June 10th. The fifth shot was taken on June 24th and the tank is very clean. The UV lamp was turned on on June 7th and worked until June 23rd. The pictures were taken with the same zoom, aperture, shutter speed, ISO and aperture. The tallest yellow artificial coral point was the focal point for everyone. If you're worried about this filter not working, my photos show it really is. This is not an instant fix and it takes time, but you can see that it gets rid of really heavy algal blooms in the aquarium. Buy this filter because it works!