I'm playing around with Fert/WC regimes in libre office calc, and made a chart of NO3 content(ppm or mg/l) with this dosing regime. (20ml/day, 50% wc every 2 weeks.) I think the urea doubles the nitrogen(?), so it looks quite good. But there is a risk that the nitrogen gets really high in some tanks.
how high can it be?? 30ppm 40ppm 50ppm?? Urea will no longer remain Urea in the water, it will convert into nitrate within hours, soon as you add it to the tank, plants goes for right away. any urea left behind convert into nitrate, second source of nitrogen for plants. EI people knows how high you can go with the nitrates without any problems, they do it all the time.