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How Soon Can I Add Fish To A New Aquarium

We have recently looked at the Nitrogen cycle in fish tank aquariums and this is a very important aspect of setting up a new aquarium and should be reviewed before taking any steps with live stock.

To put an idea of time scale on how quickly this cycle takes place, when you first set up a fish tank with new water, filter media and the like it is around 40 days for 1 complete cycle to take place. The graph below shows how this is broken down.


It is now possible to speed this process up and there are tricks of the trade to do this such as adding small amounts of food to the tank each day so it starts to break down and the cycle is started. There are also chemicals that can be added to a new tank to force it to cycle within a much shorter period of time such as the API Quick Start fluid.

As a rule of thumb though you want to be testing your aquarium water once a week to every couple of days to start with as ideal water parameters are that the Ammonia and Nitrite level are zero and Nitrate sits between 20 and 40 and remains stable at these levels. Once you are confident these levels are met then you could start to introduce fish to the aquarium however small quantities at a time and monitor the levels of Ammonia, Nitrite and Nitrate as you are bound to get a bit of a spike in these when you first introduce fish.

The key to fish keeping is patience, especially when first setting up a tank. It is always good to start with hardy fish in a tropical tank which can withstand spikes in these 3 levels and are not easily stressed, the Pearl Danio is a great example of such a starter fish and it was in fact my first tropical fish!

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API QUICK START Freshwater and Saltwater Aquarium Nitrifying Bacteria 237 ml Bottle

  • Contains one (1) API QUICK START Freshwater and Saltwater Aquarium Nitrifying Bacteria 237 ml Bottle
  • Allows instant addition of fish when starting a new aquarium
  • Reduces compounds harmful to fish when used routinely
  • Helps prevent fish loss in freshwater and saltwater aquariums
  • Use when starting a new aquarium, when adding new fish and when changing water and filter media

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£13.58 In Stock

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API 800 Test Freshwater Aquarium Water Master Test Kit

  • Contains one (1) API Freshwater master kit 800, including 7 bottles of testing solutions, 1 colour card and 4 glass tubes with cap
  • Helps monitor water quality and prevent invisible water problems that can be harmful to fish and cause fish loss
  • Accurately monitors five most vital water parameters levels in freshwater aquariums: pH, High Range PH, Ammonia, Nitrite and Nitrate
  • Designed for use in freshwater aquariums only
  • Use for weekly monitoring and when water or fish problems appear

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£29.10 In Stock