754 Absolutely a Misunderstanding (1/2)

From the expression, ”Sheds, fishbowls, pomegranate trees; men, fat dogs, chubby girls,” it could be inferred just how much the old Beijing residents loved fish and dogs.The rich and cozy life in the Siheyuan, the Chinese courtyard houses, made both dogs and girls chubby.

At the end of summer, at the beginning of the fall, there were fewer and fewer mosquitoes. Teachers were reading with rhythm in the study. They grabbed a reclining chair, sat under the shed full of purple grapes, and opened a red pomegranate. Ripe pomegranate seeds exuded sweet juice between the teeth.

An old, fat dog was lying on its stomach next to the reclining chair, lazily flicking its tongue from time to time. Dense condensation formed on the exterior wall of the fishbowl, gathered slowly under gravity, and dripped down the bowl, moistening the green rocks.

A goldfish with bulging eyes was blowing bubbles and frolicking among the dark green lotus leaves. A fair and chubby girl was running merrily and freely in the Siheyuan. From that moment on, a good life was always closely connected to pets.

The indoor people owned cats. The active, outdoor people owned dogs. Those who wished to cultivate their tastes and mold their characters owned fish.

Of course, the Siheyuan life in Beijing could no longer be enjoyed by ordinary folks. A courtyard could easily cost a billion dollars.

The older generation was not very fussy about the fish. Besides, goldfish, grass goldfish, and koi fish were coldwater fish that were resistant to low temperatures. Even in winter, it was unnecessary to move the fish tank indoors. In addition, the fish tanks in the old Beijing Siheyuan were not only for the fish. They were also used as fire hydrants. In case one house caught on fire, people drew water from the nearest fish tank to extinguish the fire.

As the greenhouse effect worsened, snowfall became rarer in the winter. But in the past, it used to be very cold in Beijing, and the fish tanks were covered with a thick layer of ice after winter began. As spring arrived and the ice melted, people would, surprisingly, find the fish swimming again in the tanks, as if they had not been affected by the frozen water.

With the development of time and technology, people became fussier with fish. Apart from goldfish, grass goldfish, and koi, there was a growing demand for fish that were rarer, more delicate, and colorful, so it was time for a variety of aquarium equipment to make their debut.

The careful fish owners would normally buy some simple equipment online or from the aquarium market, such as heating rods, pumps, filtering devices, filters, along with some fish food to complete the list. It would cost 50 to 60 yuan in total, enough to care for at least half of the freshwater fish.

The more serious fisher owners––the ones who knew how to search for information online––might add some nitrifying bacteria, commonly used fish medicine, and oxygen pumps, while changing their tank water on a regular basis. That was enough for 80% of the freshwater fish.

But raising saltwater creatures was much more complicated. Wang Qian and Li Kun stared at the eye-dazzling equipment, not knowing what to do. Zhang Zian could not possibly take care of the entire aquarium all by himself. He absolutely needed Wang Qian and Li Kun to take care of the daily tasks. Therefore, he pointed at the equipment and started explaining to them one by one.

”We know this one. Is this a filter?” they asked as they played with one device.

”Yes. But do you know what kind of filter it is?” Zhang Zian asked them.

They looked puzzled. ”This… Isn't a filter a filter? Just put some grinding wheels or filtering pads inside so that it can filter the fish poop out.”

Zhang Zian shook his head and laughed. ”Filters are not that simple. The filtration system is the most important piece of equipment in the aquarium, as they determine if the fish can live for a long time in the tanks.”

There were roughly three types of filtration: physical filtration, biological filtration, and secondary filtration. Physical filtration was the filtration of fish poop and food residue, which Wang Qian and Li Kun were referring to. Biological filtration was the nitrogen cycling system, in which the ammonia from fish poop degradation was transformed into harmless nitrates. Secondary filtration included a protein skimmer, ozone generator, calcium reactor, denitrator, UV sterilizer, etc.

For each type that Zian talked about, he pointed at the corresponding piece of equipment so that they could remember the names and shapes and not confuse them. As for the use of each device, they could take their time to learn them in the future.

Apart from the filters, there were different kinds of lights, heating rods, hydrometers, dipsticks, and other miscellaneous items.

Not all of the equipment was shipped from Germany. He ordered many of them online before returning to China. Some of the equipment was less important, so he didn't need to get the expensive ones.

Wang Qian took an aquarium fish net out of the package and asked doubtfully, ”Master, you only need a few fish nets. Why did you buy a whole box? Can you possibly use all of these nets? Or was the supplier only selling in bulk and refused to sell them individually?”

Li Kun felt the same. They both felt that a wasteful purchase was unlike Zhang Zian.

There were 100 fish nets in the box in multiple colors.

”No.” Zhang Zian shook his head. ”I was about to remind you. In the future, when you take fish out of the tank, you must remember to use a separate net for each tank––never mix them. Otherwise, if the fish in one tank get sick, it will soon infect all the fish.”