5-5-5 can sustain some of your veg phase.
During vegetative growth the plants need lots of N (nitrogen). They also need a fair amount of P (phosphorus) and K (potassium). A plant food that is 20-10-10, or 30-15-15, or something similar, with trace elements should do a very good job.
During flowering the plants need more P (phosphorus) and more K (potassium) than they did during vegetative growth. They need some N (nitrogen) but not as much as they did during vegetative growth. They also need calcium.
If you used:
--- something like 20-10-10 for vegetative growth, then try using 10-20-20 (or similar) for flowering.
--- something like 30-15-15 for vegetative growth, then try using 15-30-30 (or similar) for flowering.