The suspended ball is the simplest biofilm carrier in the catalogue: a hollow sphere that moves with the water, provides protected surface inside, and can be specified from a piece count rather than a calculation.
Also searched as: suspended ball media · bio ball media wastewater · suspended filler media · moving bed ball carrier · anaerobic tank ball media
Our suspended ball media is supplied from Φ55 mm to Φ150 mm, with a relative density of 0.92 - below water, so the ball is moved by the flow or by aeration rather than settling into a fixed bed. The published piece counts per cubic metre are anchored to the diameter, because packing of spheres follows the geometry rather than the supplier:
| Φ150 mm | About 350 pieces per m³ |
| Φ100 mm | About 1,000 pieces per m³ |
| Φ80 mm | About 2,000 pieces per m³ |
| Φ55–60 mm | Piece count and specific surface on request - confirmed against the grade, not extrapolated |
That last line is deliberate. Extrapolating a piece count to a smaller sphere assumes a packing arrangement that does not survive the change in diameter, so we confirm it per grade instead of publishing a number that will not hold.
A smaller ball gives more surface area per cubic metre and a shorter diffusion path into the biofilm. A larger ball gives a bigger protected volume, is easier to retain with a coarse screen, and is much more forgiving of high solids and of sludge that wants to coat the surface.
The decision follows the same logic as any biofilm carrier:
| High organic load, sticky solids | Larger ball - the protected volume keeps working when the surface is coated |
| Nitrification duty, cleaner water | Smaller ball - more surface in the same tank volume |
| Anaerobic or anoxic tank | Larger ball, mixed rather than aerated; the ball must be kept in suspension by the mixing energy available |
| Retrofit with coarse screens | The largest ball the screens will retain, because a ball that escapes is a blockage downstream |
Order by tank volume and fill fraction, then check the count: the piece count per cubic metre converts the volume into pieces, and the pieces are what arrive on the pallet. Ask for the count in the quotation, not only the cubic metres.
Product data: suspended ball media · technical details · alternatives: MBBR carriers · multi-faceted hollow ball · guide: how to choose media.
It follows from the diameter: about 350 per m3 at 150 mm, about 1,000 at 100 mm and about 2,000 at 80 mm. For the 55-60 mm grades we confirm the count per grade rather than extrapolating, because sphere packing does not scale linearly.
Only if the tank provides mixing or aeration energy. The published relative density is 0.92, so the ball wants to float, but it needs flow to keep it moving and to keep the biofilm thickness in check. In a tank with neither, a fixed media is the correct choice.
Carriers give more protected surface per cubic metre and a published nitrification rate; balls give a larger protected volume, simpler retention and lower cost per cubic metre. For high-load or solids-heavy duty the ball is often the practical answer; for nitrification in clean water the carrier is.
For the 55 and 60 mm grades we state specific surface and single-piece mass on request rather than publishing a derived figure from a different diameter. Ask for the grade you need and it is confirmed in writing.
You get the grade, the piece count and the fill fraction check for the mixing or aeration the tank actually has.
Request a quotationNo obligation - response within 24h (working days)