What medium are you using?
Coco? Hydro? Soil?
If coco or soil, I feed nutes when required. With coco I quite like fertigation (constant watering, before the coco is allowed to dry out too much... generally multiple times per day).
Soil it will vary, but I find I tend to water a flowering plant every 2 to 3 days in a 20L fabric pot.
For hydro, well, only when needed.
I also dislike using ml for nutes, rather look at getting an EC pen and start measuring and mixing nutes according to the EC or PPM. You will have better control over what your plants are getting.