Biofilter Specific Surface Area (SSA)

Professor Russell the Koi says: What is Biofilter Specific Surface Area?

What is Biofilter Surface Area?
Why is it Important?


Biofilter Specific Surface Area, or SSA for short, is the total available surface area of filtration media per square foot that nitrifying bacteria can live on. A biological filter, no matter what type or brand, is designed to house media that nitrifying bacteria live on to metabolize and process ammonia from pond water. 


Miss Russell the Koi says: Biofilter Specific Surface Area is important information



The bacteria live on the surfaces of what ever type of media is inside the biofilter. The higher the SSA number, the more bacteria that can live within the filter. SSA is the base figure used to calculate how much ammonia that a biological filter can process in a 24 hour period. SSA is the only common denominator across all biological filters and media. Biofilter Specific Surface Area (SSA) lets you directly compare biological pond filters.


It is impossible to know how many fish a biological filter can support, and how ammonia the biological filter can metabolize without knowing its SSA. Pond biofilter manufacturers that don’t provide you with biofilter Specific Surface Area (SSA) information is doing a disservice to you – the pond owner. Many pond biofilter manufacturers rely solely on marketing tactics to sell their pond biofilters to you. Many intentionally leave out the critical biofilter Specific Surface Area information that you need to know about what their biofilter will, and will not do. 



Russell Watergardens & Koi Clearly Lists the Biofilter Specific Surface Area (SSA) Information on Each and Every Biofilter

When purchasing a biological filter separately, or in a pond kit, or having a contractor install one for you – it is critical that you know the biofilter Specific Surface Area (SSA) of the filter. After all, if you don’t know the SSA of the filter, how will you know how many fish that filter can support in your pond?


Biofilter Specific Surface Area Tells you how much ammonia can be processed

Bio-filter Example: The Marlin Hydro Vortex™ filter has 1,354 square feet of biofilter Specific Surface Area (SSA) and is rated for up to 2,000 gallons of water. The Marlin with its 1,354 SSA can metabolize 1,354 milligrams of ammonia per day.

1,354 milligrams of ammonia is produce by 6,770 grams of fish weight. (1,354 SSA X 5 = 6,770 grams)

To calculate “How many fish can I have in my pond?” you can either divide the fish weight of 6,770 by the weight and size of fish, or divide 1,354 milligrams of ammonia by the weight and size of fish that produced it.

From the Fish Weight Chart we know that the Marlin Hydro Vortex™ filter, rated for a 2,000 gallon pond, can support
114 6″ fish (1,354 ÷ 11.85 = 114.26) or (6,770 ÷ 59.25 = 114.26) or
24 10″ fish (1,354 ÷ 54.99 = 24.62) or (6,770 ÷ 274.99 = 24.61) or
6 16″ fish (1,354 ÷ 225.21 = 6.01) or (6,770 ÷ 1,126.04 = 6.01) or
any combination of fish with ammonia totals up to 1,354, or fish weight totaling 6,770 grams.

If using a Marlin Hydro Vortex™ filter on a 1,000 gallon pond, simply divide the fish totals by two. If you’re using the filter on a 1,500 gallon pond, simply divide the fish totals by .75 …. and so on for any pond volume under 2,000 gallons. Biofilter Specific Surface Area provides you with accurate information about how many fish you can have in your pond.


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