P is holding between .04-.08 N is right at 1 ppm I dosed 10ml yesterday morning really early before I left. I wasn't here to dose any this morning and it's still holding at 1ppm. I just dosed 10ml and will check it tomorrow. I am thinking 10ml a day is going to be my dose for now. I want it to hold around 2ppm. You guys that have been doing this for awhile, where do you keep N? Did there seem to be a sweet spot?