Common questions about adding One & Only are: “I have fish in the tank can I add One & Only?” or “My tank is set-up and I have high ammonia and/or nitrite can I add One & Only”? or “If I add One & Only can I add fish immediately”?

The simple answer to all these types of questions is that you can add One & Only anytime once the tank is set-up and the water dechlorinated.

One & Only is completely non-toxic and will not harm fish, corals or invertebrates and so it can be added when fish and invertebrate are already in the tank. Just shake the bottle well and pour.

If your system is already set-up and you have high ammonia or nitrite you can add One & Only anytime to help bring the values down faster. If either the ammonia or nitrite is above 5 mg/l nitrogen we recommend a water change before adding One & Only.

In a new tank you can start to add fish once you have added One & Only. CAUTION – do not add ammonium chloride (or any type of ammonia) to a tank with fish. You have to choose either to cycle with fish or without fish (using ammonia) but not both. The quickest way to get started is to add One & Only and a few fish and slow increase the fish population.

Good fishkeeping!