Filter Media Buying Guide

Keeping your pond clean with filter media

Keeping the nitrogen cycle going is essential for the health of your pond. Filter media consists of a porous substrate placed in a filter that can alter the chemistry of the water that flows through it.

With such variety in filter medias, you have many options to choose as to which specific media is the right one to achieve maximum health for your pond. There are two types of medium that filtration can be achieved with: Mechanical & Biological.

Mechanical Media will not interfere with the chemistry of the pond water. It will strain the solids from the water as it passes through, which is very important  for the effectiveness of the media. It only needs to be replaced when it becomes difficult to clean; can't release the dirt that it holds. Coarse media is much easier to cleanse and re-use than finer filter medias but can allow fine particulates to pass through. Finer media will clarify more effectively although it can clog faster and may need to be replaced sooner. Often coarse and fine filter media is used together to achieve maximum results.

Mechanical filtration gets rid of the undesirable particles from the pond that can include fish excrement, uneaten fish food, sludge, grass clippings, leaves, dust, etc.

MediaGrade / DensityUsage
Fluval prefilter media Very coarse Catches large debris so that small media doesn't need to be cleaned as often.
Blue bonded Filter pads or foam blocks Coarse to medium Cleans most visible debris. Filter floss Fine Filters out fine particles providing crystal clear water.
Micron filter pads Extra Fine Removes extra small particulate, even parasites and bacteria.

Biological Media houses beneficial bacteria that breaks down ammonia and nitrites in the water to a less toxic nitrate. Pond beneficial bacteria survives in 55 Degrees fahrenheit and above, and needs nitrate or ammonia as its source of food as well as oxygen.

Biological media has a wide range of bacteria housing options. Smaller media, like Bio-Balls have an extremely high surface area for pond bacteria to colonize. Matala Mat offers interstitial spaces for aerobic conditions for good bacteria to thrive and is easy to clean. Traditional filter mats offer economy while providing an effective substrate for the pond bacteria to grow.