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If you keep Koi, chances are you will have encountered Ammonia by now. Ammonia is by product of the koi’s digestion and utilisation of food. It is inevitable and if allowed to build up unchecked it is fatal. You should test your pond water for ammonia regularly using a good quality dropper test kit specifically created for the koi pond environment.
The point at which ammonia becomes dangerous to a koi’s life varies based on the temperature and the pH of the water. The chart below will help you to interpret the result that your test kit gives you. It is vital to also know the temperature and pH of your water because a reading that is perfectly harmless at one pH/temp can be fatal at others.
For a full and detailed understanding of ammonia I recommend you watch my youtube video (148) Koi pond Ammonia – [Complete Guide] – YouTube
Koi pond Ammonia toxicity chart
Find your pH reading in the left hand column and your pond water temperature along the top row. Where the two intersect on the chart is the value for total ammonia (as measured by your test kit) that you can allow in your pond with Koi.
| pH | 10 C | 12 C | 14 C | 16 C | 18 C | 20 C | 22 C | 24 C | 26 C | 28 C | 30 C |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 7.0 | 10.5 | 9.52 | 8.00 | 6.90 | 5.88 | 5.00 | 4.44 | 3.85 | 3.45 | 2.94 | 2.50 |
| 7.1 | 8.70 | 7.40 | 6.25 | 5.41 | 4.76 | 4.00 | 3.51 | 3.03 | 2.70 | 2.38 | 2.00 |
| 7.2 | 6.90 | 5.88 | 5.00 | 4.35 | 3.77 | 3.17 | 2.82 | 2.41 | 2.17 | 1.89 | 1.59 |
| 7.3 | 5.41 | 4.65 | 3.92 | 3.45 | 2.88 | 2.53 | 2.22 | 1.92 | 1.72 | 1.50 | 1.27 |
| 7.4 | 4.26 | 3.70 | 3.13 | 2.74 | 2.38 | 2.02 | 1.77 | 1.54 | 1.37 | 1.19 | 1.01 |
| 7.5 | 3.39 | 2.94 | 2.50 | 2.17 | 1.89 | 1.61 | 1.41 | 1.23 | 1.09 | 0.94 | 0.81 |
| 7.6 | 2.70 | 2.35 | 2.00 | 1.72 | 1.50 | 1.28 | 1.12 | 0.98 | 0.86 | 0.75 | 0.64 |
| 7.7 | 2.17 | 1.87 | 1.59 | 1.38 | 1.20 | 1.02 | 0.90 | 0.78 | 0.69 | 0.60 | 0.51 |
| 7.8 | 1.72 | 1.48 | 1.27 | 1.10 | 0.96 | 0.82 | 0.72 | 0.59 | 0.55 | 0.48 | 0.41 |
| 7.9 | 1.37 | 1.18 | 1.01 | 0.87 | 0.76 | 0.65 | 0.57 | 0.50 | 0.44 | 0.38 | 0.33 |
| 8.0 | 1.08 | 0.94 | 0.81 | 0.70 | 0.61 | 0.52 | 0.46 | 0.40 | 0.35 | 0.30 | 0.26 |
| 8.1 | 0.87 | 0.75 | 0.64 | 0.56 | 0.49 | 0.42 | 0.37 | 0.32 | 0.28 | 0.24 | 0.21 |
| 8.2 | 0.70 | 0.60 | 0.52 | 0.45 | 0.39 | 0.34 | 0.30 | 0.26 | 0.22 | 0.20 | 0.17 |
| 8.3 | 0.56 | 0.48 | 0.41 | 0.36 | 0.32 | 0.27 | 0.24 | 0.21 | 0.18 | 0.16 | 0.14 |
| 8.4 | 0.45 | 0.39 | 0.33 | 0.29 | 0.26 | 0.22 | 0.20 | 0.17 | 0.15 | 0.13 | 0.11 |
| 8.5 | 0.36 | 0.31 | 0.27 | 0.23 | 0.20 | 0.18 | 0.16 | 0.14 | 0.12 | 0.10 | 0.09 |
