if you already have signs of pest ,,,best to attack it now , hard and fast, neem is a good preventitve, and gives the plant resistance to attacks from pests but is not efficient at killing them! there are plenty of pesticides out there, for wite fly i use chas,, or confidor, they are both agresive but as the plants are still in grow it wont be a problem!,, also try using a leaf nutrient like algamic,,,
lastly a potasium soap sollution can be added to all these items, and helps to soften the insects and there lava or eggs, thus aiding the chems to do there job
so good luck!
and welcome to the world of never ending possibilities,,,,hydroponics!