I'd just like to add a point about the water changes/resetting the tank. If you change 50% of your water once a week, you will *never* have more than a maximum of twice your weekly dosing of fertilizers. And that's without taking into account plant uptake.
For example, if you dose 3mg/l (ppm) of NO3 a day, or 21mg/l a week, your NO3 levels should never reach more that a maximum of 42mg/l. Add in what the plants can use up and the amount will be lower. If they do go above the 42mg/l in this example, you don't have enough light/CO2/plants or you're overstocked with fish.
So obviously if you change less than 50% of the water once a week, or wait longer between water changes, the "reset" aspect will vary and you should adjust your dosing accordingly. I think that the dosages recommend above are based on 50% water changes...