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I don't have a bottle in front of me, but there are specific instructions on the label for detoxifying nitrites. I believe it says to us up to 5 times the normal dosage for this. But don't quote me on it.
Another alternative is to add a small amount of aquarium salt to inhibit nitrite toxicity. It's a minute amount so its not going to affect the plants or even sensitive fish. 1/15th tsp per 10g to counteract 1ppm nitrite.