Hi, another algae issue but its one iv come across before and iv no idea how i got rid of it in the past. Here are some photos Iv just done the water change (20%) and took the water quality test, which came back with: Nitrates at 20ppm Phosphates at 0 to 0.25ppm (really hard to tell what its reading but im sure its not higher then 0.5ppm) Running all the good stuff Co2 decent flow and im dosing EI ferts at the following rates 3x a week: 2.94 ppm Nitrates 0 ppm Phosphate 1.21 ppm Magnesium 5.5 ppm Potassium Micro 3x a week Lighting 2x 24w t5 tubes over 60 litre tank on for around 7 hours a day on a timer. Whats changed Iv just increased my Nitrate to the above doses recently in the last 2 weeks and the difference it has made is massive. H.C has started to grow again and the Pogostemon helferi has also started to change to a nicer darker green and the Alternanthera reineckii has started producing red leaves on new growth. I had the algae problem before i increased the Nitrate but it appears to be getting worse and this maybe down to the nitrate increase also. Iv just changed one of the bulbs tonight to try see if that solves the problem as i know it was getting a bit old. I went for Iquatics Tropical 24w t5 enhancing the blue and red peaks and i must say im very happy with the new look. Any ideas how i can kill this type of Algae and what it is? Here's a photo of the tank after iv cut out what i can. The HC was a full carpet but i started it again due to algae issues so its just starting to grow back now but i don't dare pull on the algae too much as it pulls the HC out.