As you can see its on most leaves. It will wipe off if you rub hard enough. Lighting is two pl 18watt bulbs 6400k white and the tropical colour not sure of the colour rating. Pressurised co2 at 1bps green drop checker 45litre tank Nitrates are around 40ppm Phosphates around 5ppm Ammonia 0ppm Nitrite 0ppm Dosing liquid ei dosing 3x micro 3x Macro per week. My macro now only consists of potassium sulphate and magnesium sulphate as I feel nitrates and phosphates are a little high? Only started doing this for the past 5 days previous to that I was dosing extra nitrates and phosphates. Only at the recommended doses of 10ppm and 2ppm. Any idea what the cause is or what the best plan of action is? Increase co2 maybe? Iv increased my water changes to 50% a week from 20% to lower nitrates and phosphates a bit. Not sure if I should wait it out another week and see how it gets on but iv had this algae a while now. Months, but only recently in the last month managed to get my dosing more regular and on time.