It's not a "balance", its weekly 50-70% water changes that reduce NO3 down only to be dosed up to a certain concentration for max plant uptake (Not just NO3, but all nutrients we dose).
Just because there is a trace of NO3 in the water, does not mean that plants can utilize it. They can't "choose" which nutrient they want to uptake. If light + CO2 are driving fast growth, we need the 40ppm concentration of NO3 so the plant's N requirements are met for it's growth speed.
Make sense? Or no? I can try and re-word it if needed.[/QUOTE]
Yes, that makes sense...although I do see this as a balance of sorts.
So a 20-40ppm nitrate range would be ideal for fish and plant health. That is exactly what I am aiming for. After switching to thrive I was seeing 40ppm nitrate a day or two after my water change and it was going up and required a mid week water change to keep it from going over 40. I can remove the nitra-zorb and see if it goes back up but wouldn't it be better if the tank is more consistently in that 20-40 range?