Isolite

http://www.gardenweb.com/isolite/

"The World's Best Pond Biological Filtration Media" - Featuring - ISOLITE, porous ceramic

ISOLITE is ideally suited for the immobilization of microbes and enzymes for ponds, mine waste continuous wastewater treatment processes, septic systems, leach fields, wetland construction, aquaria, and sewage treatment.

Q. I use gravel and sand as a filtration medium. How will ISOLITE benefit me?
A. A cubic foot of gravel adds about 150 square feet of surface area on which microbes attach, a cubic foot of sand adds about 1,500 square feet, and, because of its internal pore space, a cubic foot of ISOLITE adds almost 700,000 square feet of internal surface area in which microorganisms live and thrive.

Q. Why is internal pore space so important, and why is ISOLITE such an effective medium?
A. Internal pores must be at least 1 micron in diameter to sustain living organisms. Most of ISOLITE's pores are greater than 1 micron in diameter. Internal pore space is important because it protects treatment microorganisms from flushing from each ISOLITE granule, it provides stable support for continuous microbial growth, it optimizes concentration /viability of treatment bacteria, and it provides matrix stability.

Q. How much ISOLITE do I use?
A. There is no set application rate for biological filtration. The more that is used, the more efficient your treatment will be. Because ISOLITE is sold in 5 different sizes, these different sizes can be mixed to achieve different ratios of flow-through. The 1 mm diameter size is used for sand filters, the 2 mm size for coarse sand filters, the 4 mm & 6 mm diameter size for pea gravel filters, and the 10 mm diameter size for larger gravel filters.