I typically will use 20-20-20 with some fish fertilizer. I have used bloom booster, but I use it blended 1:1 with regular Miracle Gro (24-8-16). Comes out to 19.5-19-15.5. Close enough for me. I buy a hodge podge of whatever is on sale and just do some math to blend it into a 1:1:1 ish mix. When I first started out I followed Ascpete’s ratio’s of 2-1-3, 1-1-2, 1-1-1 (in order of preference). The math was just easier on a 1-1-1.