You really dont need them as you do have enough LR
for good biological filtration. The skimmer will be great for removing DOC
`s which will end up as nitrates if not removed. You could save them and use for times when you need GAC
or purigen in the tank. As I mentioned in another thread the nitrates can be taken care of with good water management. But in all the LR
+ skimmer + PH`s for good water flow is really all you need.