Water flow rate over bio filter media

[Michael1212]

Does anyone have any knowledge on the relationship between water flow rate and the effectiveness of biological filter material? How would a bag of bio balls in the middle of a sump refrigerium perform compared to the same bag having all flow directed through them via some baffles? Would performance go up if an airstone was placed underneath or is the oxygen in the water already more than sufficient?

 

[hypnogogia]

If your bio balls are in a bag floating in your refugium, then presumably some water will be able to by pass them. Is that what you want? The old tunze overhead filter system worked on similar principal whereby some water that had been filtered was then bypassed over a trickle filter. It worked really well and co trolled ammonia, nitrite and nitrate. Most sump design I’ve seen recently though, all the water passes through the biological medium.

 

[Michael1212]

I'm not familiar with the Tunze filter system. I've seen some people place bags of bio media in a sump / in a tank, and I'm just wondering how effective that is.

 

[Zeus.]

Would performance go up if an airstone was placed underneath or is the oxygen in the water already more than sufficient?

Yes, if the microbes was O2 limited

Why are you after more bio media ? if doing a planted tank your plants roots have the largest surface area for biological filtration, esp when established, if planning a lot of fish or fish only then its another story.

If planning CO2 injection an airstone will drive more CO2 off in the sump also during the CO2 period