agree, stop fertilizing until you get the numbers down. i would just continue doing your normal water changes, and monitor water quality. once things are under control, try 1 pump of easy green a week. if one or two particular plants show signs they are not getting enough nutrients, then you can put in a root tab by that plant. with so many root tabs, and essentially double dosing easy green, it will just take some time for it to balance back out. IMO large water changes, especially in smaller tanks can cause as many problems as what you are trying to solve. if the fish arent distressed, dont do big water changes. 25-30% is plenty. if its not enough, do 25-30 every few days vs one large change.