| Once you have set up your tropical aquarium the | | | | is essential to test the levels and to indicate when |
| next step is to 'cycle' it. This process produces | | | | cycling is complete. |
| beneficial bacteria that will process the waste | | | | The Fishless Cycling Method |
| ammonia from your fish and convert it into nitrites | | | | Extra aeration is recommended while cycling as |
| and then into relatively harmless nitrates. After adding | | | | bacteria need oxygen to grow. Increase the aeration |
| fish to an uncycled tank the toxic ammonia and nitrite | | | | through the tank and filter if possible. You could add |
| levels will rise to a dangerous high until there are | | | | an extra air stone or even use an extra pump if one |
| sufficient numbers of bacteria to convert them into | | | | is available. Add your bacteria culture, then add about |
| less toxic nitrates. In order to overcome this | | | | a teaspoon of ammonia for a small tank. Increase this |
| methods have been devised to encourage the | | | | for a larger tank. Allow about an hour for the |
| growth of the bacteria. The traditional method is to | | | | ammonia to circulate then test. The ammonia level |
| add a few 'hardy' fish that will produce ammonia to | | | | should be between 5 mg/L (or 5ppm). Add some |
| encourage bacteria growth while the tank is 'cycling'. | | | | more ammonia if the level is too low. Leave the tank |
| This method is very stressful for the fish, many of | | | | alone for a few days then test again. |
| which die or are damaged by the process. The toxic | | | | At this stage the ammonia level should begin to drop |
| ammonia burns the gills and leads to permanent | | | | and the nitrite level to rise. This means that the |
| damage. At the end of the 'cycling' you are left with | | | | bacteria are doing their job of processing the |
| fish in poor condition which you may not want in | | | | ammonia. Add some more ammonia when it drops to |
| your aquarium. | | | | zero to give the bacteria more to work on. The |
| A better, more humane method to cycle the tank is | | | | nitrite level should rise until it reaches a maximum |
| to use a fishless cycling method. It uses household | | | | then begin to drop as the nitrites are converted into |
| ammonia as a source, rather than live fish, and a | | | | relatively harmless nitrates. Three or four days after |
| bacteria culture obtained from a healthy tank or | | | | the maximum nitrite levels are seen the nitrite level |
| purchased from an aquarium supplier. | | | | should drop to zero. The cycling is now complete. |
| The Bacteria Starter Culture | | | | Change about 50-70% of the water, carefully so as |
| You can obtain a starter bacteria culture by adding | | | | not to disturb the filter or the gravel bed where the |
| some gravel, filter medium or rock from a healthy, | | | | bacteria are colonised. Reset the temperature to |
| aged tropical fish tank. If you do not have a source | | | | 25°C, or the recommended temperature for |
| there are commercial products available, for example | | | | your intended fish and allow the temperature to |
| StressZyme or Hagen's Cycle. The culture will give a | | | | stabilise for a few hours. Retest for ammonia and |
| quick start to producing a colony of bacteria but you | | | | nitrites and if the levels are zero you can now begin |
| can also use this method without a starter culture. It | | | | to add some fish. |
| will take a bit longer then to cycle your tank. | | | | It is possible after cycling the tank to add all the fish |
| The Ammonia | | | | in one go but this will result in a spike in the ammonia |
| Purchase some unscented, additive free 100% | | | | and nitrite levels which is stressful for the fish and |
| ammonia. Some aquarium supply shops are now | | | | could cause them to become diseased. adding the |
| selling ammonia for this purpose. If you know a | | | | fish slowly will allow the bacteria to grow to cope |
| chemist or science teacher they may be able to get | | | | with the added levels of ammonia excreted by the |
| you some pure ammonia from a laboratory supplier.. | | | | fish. Even for a fully cycled tank it is advisable to |
| The Tank Temperature | | | | gradually add the fish. aim to take about a month to |
| The bacteria (Nitrosomonas and Nitrobacter) thrive | | | | fully stock the tank. |
| best at higher temperature than is usually used for a | | | | A fishless cycling method is more efficient and |
| tropical tank so during the cycling increase the | | | | produces a fully cycled tank in a much shorter time |
| temperature to between 30 and 35 C (85-95F). | | | | than the traditional method of using hardy fish. It is |
| When you add the fish you can turn it down again. | | | | also more humane and you will not be left with |
| Testing Kit | | | | unwanted, often damaged fish, at the end. |
| A testing kit to check the ammonia and nitrite levels | | | | |