you need to have better knowledge on what type of bloom nutrient you are considering giving them. I too have the same sized pots but to give you the dilution rate I use with the specific nutrient I am using could leave your plants being under fed or over fed.
suggestion: find out what type of nutrient you have, would help if its in its original packaging(not to mention the original packaging would most likely contain the dilution rate) you can then search online for application rate(for example if you have roots organics, and the product is called buddha bloom, search 'roots organic buddha bloom dilution rate/application rate'). Be careful because not all nutrients are meant to be used the same way, some are used as foliar spray, some could be top soil(throwing the mix ontop of soil then watering in), and some can be mixed in a tank or bucket and watered with the solution.