From Bio balls to Live rock???

ur in a bit of a pickle if u wana switch because if ur system is 2+ years all the bacteria u need is on those bio ball so if u get rid if them there goes ur bacteria(and 2 yers work). i use both in my canister filter and most large tanks i have worked on and set up do best on live rock. it doesnt need to be compleatly submurged or have light but would be better with light because it would add photosynthisis to ur filter system removing co2 and adding o2.

Do you have a pre-filter on your wet-dry? What are you nitrates? Water change frequency and size? What all is in the tank? Wet-dry setups can be built to be effective and manageable, and if your setup is healthy and happy with current management, why change it? Just because other people run a different seutp with equal success?

You want the live rock completely submerged--having water trickle over the rock will result in areas that are always dry, and won't support bacteria, and will also potentially trap solid wastes where cleaners can't get to them. You can make the transition by removing some of the bioballs and replacing it with good live rock--and just keep rotating out the bioballs in favor of more live rock. The rock can go in the main tank, though--the fish will appreciate the hiding places, and the food source. If you already have adequate live rock in the main tank, then you can simply phase the bioballs out--remove a handfull or 2 each week, and the remaining bacteria colonies already present on the rock will expand to take the full load.

The live rock will be fine without lighting--the bacteria don't care at all.