Bioballs vs LR rubble in Sump.

[Todd]

I understand that Bioballs when used in a wet/dry type system can contribute to nitrates due to accumulation of detritus.

However if Bioballs were added to a sump in a relatively detritus free area, what difference would this be from adding LR rubble in an attempt to provide an area for beneficial bacteria to colonize?

I have been unable to think of a good reason, yet notice that there is little use of bioballs in reef tanks. Could someone enlighten me as to why they are not used in this manner?

[fencer]

Bioballs are mean to similate rubble (sort of). They both provide surface area for bacterial growth. They differ as bioballs are more effective at gas exchange and the random path they provide for the water. Rubble channels. Really bioballs are not made to be immersed in water. Any sludge coming off fall into the lower chambers wher it can be siphoned off. They still use bioballs in wastewater treatment facilities. I have bioballs running on the outflow of the tank and the exit stream flows into the fuge with live rock and skimmers.

[Doug]

Todd,
Its not really the detritus that creates the nitrate, but the very efficient wet/dry filtration. They convert the ammonia to nitrite and then to nitrates, which is their job. And they do it well.

Its best used in systems with not much or limited live rock or in stores, etc. where large increases in bio loads needs to be handled. Live rock & sand beds provide all the bio capability one needs in a normal fish only or reef tank. Both the sand bed & oxygen starved areas, {which bio balls dont have}, of the live rock, provide a place where denitrification bacteria can thrive.

The use of rubble in a sump can contribute to detritus, which in turn helps promote phosphates & nitrates. Most use it in a refugium, that receives cleaner, filtered water, so the accumulation is less.

I do know of aquarists with not much live rock and they use some type of wet/dry filter. They also use a sand bed or algaes in a sump to help with nitrate removal. Some also employ the sulphur reactors for that purpose.