Should I use bio-balls w/ LIVE rock?

[si12ius]

I have a 90 gallon tank with a 40 gallon sump filled up half way so I would say it has 25 gallons in the sump. I also have a 2.5 inch sand bed with around 75 lbs of live rock. Do you think I can add about 25 bioballs my buddy gave me to make up for the 25 more lbs of live rock I need?

 

[nycbob]

i would leave the bioballs out since they can cause nitrate, if not clean on a regular basis.

 

[nordy]

25 bioballs is not a large number, even though they have a fairly large surface area. If you use them, as nycbob says, clean them regularly, and install them so they are dripped on and not submerged. The first time I cleaned the bioballs in my tank, they were covered w/algae and stuff, so I clean them about once a month now and they stay pretty clean.

 

[apos]

Yeah: if you do use em, they really need to TRULY be a wet/dry (i.e. water rushes over them, but doesn't submerge most of them), and not just sitting in water in a chamber of the sump.
There is no hard and fast rule on how much LR you need, really. The amount of surface area needed for biofiltration all depends on the laod your tank has anyway.