Hi there,
I run a heavily planted 90G, pressurized C02 tank and yes at some point it will be necessary to start dosing. I am currently using the "EI" method for dosing and you can get the ferts from here: http://www.aquariumfertilizer.com/
I ordered mine and started dosing around a month ago. It was packaged nicely and came within 5-7 business days after ordered. Lots of improvement so far in plant growth and color. Watch dosing KN03 as you may already have enough. Generally 10-20ppm is enough N03.
Pickup the CSM +B for trace from there as well. If you have any questions, let me know. No I don't work for this website, just a happy customer lol.
Regards,
Daniel
Price?