Live rock is beneficial and can be used like stated above. If you have 1-1.5 lbs of LR
in your DT though, you won't see any additional benefit. The use of macro algae is always acceptable and should be what you are replacing those bio balls with. Cheato is the most commonly used and pretty cheap. It can also be used with a bare bottom, which is helpful in most applications since it is common to have all the LR
in the DT. Only time this isn't the case is for those who are looking for a more "open" look.