I am thinking that you are still not shaking bottle number 2 enough, both in the bottle and when mixed with number 1. As I like to say: "Shake that bottle like it owes you money!"
You have so much stock that your nitrate levels don't make any sense unless you literally just changed 75+% of your water. Nitrates represent the end product of the nitrogen cycle and have no way of exiting the tank except through water changes and/or significant hydroponics set up and so will continue to raise. I have a 125 with one oscar, one severum and a pleco and the nitrates go up to 20ppm by end of the week. I do 90% water changes once a week. I have lots of filtration (x15 turnover) and have two pothos filters running on the tank.