Yes , in flower food is put a bacteria killer , which help to keep the water clear. https://centimo.nl/product/postharvest-preservation-liquid-anti-bacteria/%E2%80%8B
To activate the stomata in flowers or foliage more. So absorbable flower dye will work much better during the absorb proces . Just mix 2% into your absorbable dye solution
Place a small dab of glue on a square of plastic. Add a drop of glue to the design area where the flower will sit. Dip the end of the flower stem into the glue. Insert the flower into the design and hold for a few seconds for it to adhere.