I would suggest before altering or adding anything to the system, look at it as a matter of need
and nothing else. If there in no need for something, then it is best to leave it as is. If anything, the best filtration media is a natural one that allows for proper nitrification such as LR
Since the tank is cycling, the only thing you need to do is monitor NH3
. Not much else. If you are using a pure water source and there are no measurable levels of unwanted elements in the water that will fuel unwanted algae growth, you do not need anything else.