Hangtai Aquarium: Treat Fishkeeping as Fun, and You Can Become a Master Without Rigidly Sticking to Formulas

Many articles on biological filtration, though highly beneficial, are a bit too technical. In fact, the principle is simple: so-called biological filtration is just the concept of "old water" that Chinese fishkeepers talk about. Old water is the most suitable water for keeping fish.

So, creating this kind of old water requires methods; from a scientific perspective, old water works because of nitrifying bacteria in the water. How to produce and maintain nitrifying bacteria in the water, that is, the process of establishing and maintaining a biological system, in the Chinese fishkeeping tradition means the process by which water, after drying, cycling with test fish, filtration, and so on, changes from new water into old water, and how to keep old water from turning back into clear water or even dead water.

Nitrifying bacteria need oxygen, water flow, and so on. Maintaining old water follows the same principle. Ever since the term biological filtration appeared, nitrifying bacteria, activated carbon, ammonia-absorbing stones... and other bio-related things have emerged accordingly. These methods are certainly useful and scientific. But is nitrifying bacteria really that complicated?

In fact, with a powerful circulating filtration system, lighting, and the necessary cycling with test fish, the water in the tank will naturally become old water, and there is no need to buy a whole pile of things for nitrifying bacteria. Chinese people have a longer history of fishkeeping than Westerners, and they keep fish very well. Add to that some Western methods and equipment, and you can keep fish even better. That is to say, there is no need to be too superstitious about Western methods; combining local and Western approaches is better. And you do not need to spend so much money. Specifically, there are the following points:

1. Whether the pumping force of the water pump can draw in waste

Observe the circulation of water in the tank and see whether fish feces can be drawn in by the pump. Adjust the pump intake and the filter trough outlet to the best positions so that feces are drawn in by the pump with the water flow and enter the filter trough. To make the pump work better, buy one slightly larger than usual; that is, for a 1.2 m tank, if a 30 W pump should be used, buy a 36 W one. The key is not to leave feces in the tank. In addition, those keeping discus are afraid the water is too strong and will batter the fish, so you can point the outlet toward the tank wall, letting the water hit the wall inside the tank and then flow back to the pump intake.

2. You can choose thicker filter cotton as a bacterial bed

This is quite sufficient. Relatively thick cotton can cultivate bacterial strains very well, so there is no need to spend more money buying bacterial strains, bacterial beds, and so on. By comparison, sponge is better, more economical and practical. Filter cotton will become tattered after being washed several times and needs to be replaced, while sponge lasts longer. Although each wash removes dirt and also washes away some nitrifying bacteria, enough nitrifying bacteria will remain as seeds. With the pump doing its job, plus sponge serving both as filtration and as a nitrifying bacterial bed, and with the tank walls and tank decorations all being good bacterial beds, old water is produced. In addition, because the filter cotton is thicker, water may accumulate in an overhead filter trough and overflow; just raise the retaining grid inside the trough a bit. Note: the sponge should be the fine, dense kind. New sponge has poorer permeability, but it will be fine after being used for a while.

3. Do not worry about or obsess over formulas

As for pH value and hardness, handle these flexibly according to the situation. Keeping fish is entertainment; making it like academic research is too tiring. The fish we keep are mostly not wild; passed down generation after generation, they have basically adapted to the pH of our water. Buying fish from the south to keep in the north is ultimately only a minority case. As long as the water is kept in an old-water state, the pH and hardness of this water will be fine.

4. Regular water changes cannot be ignored

Even if the water is not cloudy, water changes are still necessary, 1/3 or 1/4 each time, but with what was said above, they do not need to be so frequent. Many friends have a misconception: they never change the water themselves, and when the water gets low they just add water. In fact, this is much the same, because the purpose of changing water is to add new water to the fish tank to break down trace toxins in the old water. If you can add water regularly, you can also ignore the step of changing water.

Summary of Experience

In the past, Chinese people kept fish in basins and used the siphon method, and old water was maintained for only a short time. Today, with pumps, old water in the tank can be maintained for a long time. To keep water in an old-water state, the pump is crucial. The pump circulates the water, and filter cotton or sponge both filters and acts as a bacterial bed. For a 1.2 m tank, use one external canister filter with both layers using sponge. No ammonia-absorbing stones, bacterial strains, or the like were ever put in; the sponge fully played this role.

The longer the sponge is used, the more precious these two pieces of sponge become. Because they not only block dirt, but also act as a bacterial bed. Old water (that is, the biological cycle) is thus produced and maintained. If, when setting up a new tank for fishkeeping, you can take two pieces of filter cotton from the filter trough of an old tank, then establishing old water will yield twice the result with half the effort.

Chinese people have a long history of fishkeeping, but unfortunately there are few scientific summaries; there is much experience accumulated among the people, but when spoken it has no formulas and does not form written rules, while foreign fishkeeping stresses science: pH, nitrifying bacteria, biological, physical, and so on. Fishkeeping indeed requires this professional knowledge, but if it becomes too professional it turns into academic research. Operability and enjoyment are then greatly reduced. It makes beginners in fishkeeping feel intimidated or even discouraged. I think it is better to combine traditional Chinese fishkeeping wisdom with scientific basis. It is more enjoyable and more operable. Water changes, and fish grow, and the water and fish in the tank will change accordingly; using only some data is far from a substitute.

My WeChat public account is guanshangyu-88. If you have anything unclear about ornamental fish breeding, you can contact me anytime!