Thanks for the kind words to all.
The water perameters - pH of 6.8 pre co2, and 6.2 after co2 injection (sitting still for 48hrs the pH is 7.4). KH is 2, nitrates of approx 20-40, TDS is between 150-300ppm. I don’t test for nutrient parameters. I use PPS PRO dosing, total root tabs from aquariumplants.com. The tank has been setup since the summer of 2011. Next step will be to redo the substrate with all ADA amazonia, and a switch to LEDs at some point.
OK thank you. Your dKH is lower than what I aim for but its obviously working well. I will also try the switch to T5HO and hope for better results.