I'm running my 240ltr with a 2kg Co2 tank, it is supplying 2 spiro 9000 diffusers which are running at around 3 bps each, yet I still have a darkish green drop checker all the time and algae issues. Anyone got any ideas? Lights are 2X39W T8's on for 8 hours a day, Co2 on 2 hours before lights on and off 2 hours before lights off. Flow rate is 1 X 3000lph power head, 1 X Eheim 2073 and 1 X Eheim 2076. I am EI dosing also. My 2kg Co2 bottle has gone into the red today, It was last filled 3 weeks ago.