Should I change my subrate or?

I currently have a 55 gallon tank that's been established for almost a year now, but I'm not sire what to do in regard of sunrate nutrients for my plants, I know I could use root tabs but do they really work that well? And I was wondering if it'd be viable to change the subcategories all together and replant the tank, or would the mess up my tanks cycle? Currently using a small sized gravel and sand mixture about 2 inches deep