Can somebody tell me about the Fish Method in counting bacteria?

Question

Mainly relating to bifidobacteria count.

Answer 1

The basic ingredients for cycling a tank are a starter culture of nitrifying bacteria (innoculum), ammonia, water, oxygen, and a substrate for the bacteria. I am assuming that your aquarium has been setup competently, so that it has water, biofiltration media (substrate), and aeration (oxygen). This leaves the ammonia and the bacteria.
I use clear, unscented, no additives, 100% pure household ammonia from the supermarket. A quart costs less than a dollar and might last you for years. You will want to place it in a container that allows dispensing by drops. An old water conditioner bottle with the right type of top is good: BE SURE TO LABEL IT! Keep it out of the reach of children. Alternatively, some aquarium stores have started to sell bottles of Ammonium Chloride for this purpose.

A starter culture of Bacteria can be added by two methods. Some material from an established aquarium can provide the needed innoculum: some water, a piece of used filter material, a decorative object, a handful of gravel. This shares the disadvantage of the donor media method of bringing in pathogens. However, if the donor tank has been in good health, there may be no compelling reason to avoid donor material. The second method is to use one of the commercial preparations of nitrifying bacteria. I have had good results with Hagen's Cycle