For many years I use Tetra Bactoyzm what I am one capsule in the two chambers of the water filter give (I have a 90 liter tank). After about 12 hours the water is milky turbid, indicating the onset of bacterial activity. But a day later, the water is completely clear again. Once a month I give to refresh the cultures a table directly into the water; the shell dissolves without residue and gives the bacteria cultures freely. A regular test the water parameters such as nitrate and nitrate certifies that the product has a very good activity, ie pollutants are almost completely degraded by the bacteria, which reduces the amount of water change in particular in connection with Tetra AquaSafe. All in all a highly recommendable product!
What else is interesting for newcomers who set up their aquarium for the first time: the extremely short bioactivity in the aquarium does not have to be a month of fish renounce (as long as an aquarium takes about until it "retracted" and the bacterial cultures stable have built up), but you can already use the first fish after a few days.
