What’s the difference between this bonded filter pad product and 100 micron Polishing filter pad, both from Aquatic Experts?

Our Premium Dual Density filter pad traps both coarse and fine particles and can be used in most filters as the only mechanical filtration needed. Our 100 micron polishing pad is much thinner and is designed to be used to remove very fine particles from aquarium water. Hence it gives a polished looked to the water. Many hobbyists will use our Premium Dual Density pad and our polishing pad together in their filters. The aquarium water needs to flow through our premium pad first before entering the polishing pad. This allows the larger particles to be remove before getting to the polish pad therefore increasing the time before you will need to clean or change the polishing pad.