bio-ball removal from 125 established reef tank

[micromount]

I want to remove the bio-balls from wet-dry system and drill out a 10 gal tank and connect to the wet-dry The refugium will be put in the tank. I plan on putting the phosban reactor in the compartment where the bio-balls are. The return pipe goes right against the cover so pipes will have to be cut. So it will be easier to take bio-balls out all at once. Am I courting disaster taking them all out at once?
My son works at LFS and can keep the fish at store if I can get them out. Would it be better to remove the fish for several weeks?

 

[gparr]

I would remove the bioballs gradually over a six-week span, then make your system changes. Monitor your water parameters regularly, particularly ammonia and nitrites. While bioballs become a nitrate factory over time, they still carry significant amounts of bacteria that break down ammonia and nitrites. Remove them too quickly and the bacterial colonies elsewhere in your system, particularly your live rock, will have a difficult time keeping up. As a result you might have ammonia and/or nitrite spikes. As with every other change you make in a reef system, go slowly.
Gary