A run-in phase of between two and four weeks is generally required when setting up a new freshwater aquarium. For instance, this period gives the filter bacteria enough time to multiply so that they can then perform their essential role; namely biological filtering of the aquarium water. If these bacteria are absent, this often results in high concentrations of (poisonous) ammonia, which is a product of fish protein metabolism and other decomposition processes. The equally toxic substance nitrite is also produced as an interim stage during the nitrification process, which involves converting poisonous ammonia to nitrate. Tetra SafeStart contains the essential live, nitrifying filter bacteria, which are specially cultivated in Tetra's biofarm. These bacteria kick-start the process of nitrification in the aquarium and have been shown to break down the poisonous substances ammonia and nitrite into harmless nitrate, or to even prevent these toxic intermediate products from accumulating in the first place. Once the filter has been activated, this will result in healthy water conditions and a biologically active habitat. It is therefore a good idea to not only use Tetra SafeStart when setting up a new aquarium, but also after every major partial water change, each time the filter is cleaned or after treating the tank with medication. Ideally, it should be used alongside Tetra AquaSafe, which encourages the bacteria to settle. Tetra SafeStart is available in 50 ml, 100 ml and 250 ml containers and is suitable for use in all types of freshwater aquaria. Plus: we also offer Tetra Marine SafeStart, designed specifically for use in marine aquaria.