Why are bio balls better in a trickle filter?

[Freezekougra]

I always hear that they are bad submersed and only good with air saturation or something like that

So in a trickle filter, what makes bio balls a better option than say, substrat pro or matrix?


Edit: New question
-Are filters better as a trickle filter or submersed? I want to build an overhead filter...submersed would allow me to put some plants on it so the filter looks better

-Are bio balls all the same size? One site selling them tells me 60 pieces = 1 gallon, while another site is telling me 80 pieces = 1 gallon.

 

[Freezekougra]

bump

 

[redman88]

i would guess that to get the max effect from the bio-balls you need air for the bacteria. i could be wrong though

 

[West1]

You can get away with putting them underwater and adding a air line at the bottom.
The best is to have the water pass through the bioballs with exposure to air

 

[mrunlucky07]

The main concept behind bio balls is that in a shower filter, where water is crashing over them, not just trickling, ammonia directly off gasses and skips the nitrite-nitrate stage. In theory not as much nitrate will be made and rise as quickly in a tank. The large voids in the balls cause falling water and uneven shear of the water mixing in more air and off gassing more.

So in a trickle filter, what makes bio balls a better option than say, substrat pro or matrix?

The voids in the balls, if you pack a media tightly there will be no crashing and off gassing. Some people recommend linking the balls so there is even more open space. Its about the open space and not necessarily the surface area.

-Are filters better as a trickle filter or submersed? I want to build an overhead filter...submersed would allow me to put some plants on it so the filter looks better

Best bet is both, they are two different animals.

-Are bio balls all the same size? One site selling them tells me 60 pieces = 1 gallon, while another site is telling me 80 pieces = 1 gallon.

They come in many sizes. The smaller the more surface area generally.