Average
Fish Weights and
Pond Stocking Levels
Koi and Pond Fish Weight Chart
To Use This Chart Correctly:
- Calculate the Total Specific Surface Area (SSA) of your biological filter.
- Calculate the Total Ammonia your biological filter can metabolize per day.
- Calculate the Total Fish Waste your biological filter can metabolize per day.
- Multiply the Total Fish Waste by The 1,000 Gallon Factor to determine the Max Fish Weight your biological filter, pond, and water volume can support.
- Divide the Max Fish Weight by the length of the fish in your pond.
Jump directly to the Fish Weight chart below
What is Specific Surface Area (SSA), and Why is it Important?
Filter Media Specific Surface Area (SSA) Charts
Find your SSA, fish waste, and total fish weight your filter can support here
The SSA of your filter will tell you how much total fish weight, ammonia, and fish waste in can metabolize in a 24 hour period. The chart below helps you understand what sizes, and quantities of fish your filter can support.
You MUST know the Total SSA of your filter to know how many fish you can place in your pond!
Fish Weights, Lengths, Ammonia Produced, and
Waste Produced
Fish Length |
Weight in Ounces |
Weight in Grams |
Ammonia Produced in MG/24 hr | Waste Produced in Grams/24 hr |
1" |
.01 |
.28 |
0.028 | 0.0924 |
2" |
.08 |
2.27 |
0.227 | 0.7491 |
3" |
.26 |
7.37 |
0.737 | 2.4321 |
4" |
.62 |
17.58 |
1.758 | 5.8014 |
5" |
1.21 |
34.30 |
3.43 | 11.319 |
6" |
2.09 |
59.25 |
5.925 | 19.5525 |
7" |
3.33 |
94.40 |
9.44 | 31.152 |
8" |
4.96 |
140.61 |
14.061 | 46.4013 |
9" |
7.07 |
200.43 |
20.043 | 66.1419 |
10" |
9.70 |
274.99 |
27.499 | 90.7467 |
12" |
16.76 |
475.14 |
47.514 | 156.7962 |
14" |
26.61 |
754.38 |
75.438 | 248.9454 |
16" |
39.72 |
1,126.04 |
112.604 | 371.5932 |
18" |
56.55 |
1,603.17 |
160.317 | 529.0461 |
20" |
77.58 |
2,199.36 |
219.936 | 725.7888 |
22" |
103.25 |
2,927.10 |
292.71 | 965.943 |
24" |
134.05 |
3,800.25 |
380.025 | 1,254.0825 |
26" |
170.43 |
4,831.61 |
483.161 | 1,594.4313 |
28" |
212.87 |
6,034.76 |
603.476 | 1,991.4708 |
30" |
261.82 |
7,422.47 |
742.247 | 2,449.4151 |
Remember, when comparing biological filters, it is important to know the bacteria Specific Surface Area (SSA) it has. This allows you to compare "apples to apples" as the SSA is the most important part of the biological filter. The SSA enables you to calculate the total fish waste it can metabolize, and the total number of fish - by size - that the filter can support.
If the biological filter you are looking at doesn't provide you with basic SSA information, you should question why that manufacturer is withholding that information from you. Its your pond, and they're your fish.....you deserve to know what that filter can support.
The most common problems of excessive algae, and sick fish are directly related to improperly sized biological filters - filters with low SSA numbers. Before purchasing a pond kit that includes a biological filter, or a stand-alone biological filter - make sure you know what you are getting - make sure to know the SSA.
