Fish and Aquarium・Invertebrates｜The 5 Deadliest Mistakes Keepers Make (Plain-Language Version, No Jargon)

FAQ

Rushing to add fish and shrimp before the new tank has "matured" — why does this go wrong?

Rushing to add fish and shrimp before the new tank has "matured". When a tank has just been set up, the beneficial bacteria that break down fish waste and food scraps are not yet there, so putting in too many fish and shrimp at this point amounts to leaving them soaking in the toxins of their own waste, and the whole tank often dies off within a few days. The correct approach: let the tank run empty for a while to "mature the water", test that water quality is stable, and only then add fish slowly.

新しい水槽がまだ「立ち上がって」いないのに、急いで魚やエビを入れる——なぜこれで問題が起きるのですか。 — 新しい水槽がまだ「立ち上がって」いないのに、急いで魚やエビを入れる。 水槽を設置したばかりのときは、中に魚のフンや残餌を分解できる有益な細菌がまだいません。この段階で魚やエビをたくさん入れると、自分の排泄物が生む毒の中に浸けておくのと同じことになり、数日のうちに全滅することがよくあります。正しいやり方：まず水槽をしばらく空のまま回して「水を育て」、水質が安定したことを確認してから少しずつ魚を足していきます。

Rushing to add fish and shrimp before the new tank has "matured" — why does this go wrong? — Rushing to add fish and shrimp before the new tank has "matured". When a tank has just been set up, the beneficial bacteria that break down fish waste and food scraps are not yet there, so putting in too many fish and shrimp at this point amounts to leaving them soaking in the toxins of their own waste, and the whole tank often dies off within a few days. The correct approach: let the tank run empty for a while to "mature the water", test that water quality is stable, and only then add fish slowly.

Changing too much water at once, with too great a temperature difference, and using tap water that has not been dechlorinated first — why does this go wrong?

Changing too much water at once, with too great a temperature difference, and using tap water that has not been dechlorinated first. Many people assume the more water you change the cleaner it is, but changing more than half at once instead subjects the fish and shrimp to a violent water-quality and temperature shock and kills them outright. The chlorine in tap water is there to kill bacteria, and it is just as corrosive to fish gills, so it must always be treated before a water change.

一度に大量の水換えをする、水温差が大きすぎる、水道水の塩素を抜いていない——なぜこれで問題が起きるのですか。 — 一度に大量の水換えをする、水温差が大きすぎる、水道水の塩素を抜いていない。 水換えはきれいにすればするほどよいと考える人が多いのですが、一度に大半を換えると、かえって魚やエビが激しい水質と温度の変化にさらされ、そのままショック死することがあります。水道水の塩素は殺菌のために入っているもので、魚のえらに対しても同じように腐食性があります。水換えの前に必ず処理してください。

Changing too much water at once, with too great a temperature difference, and using tap water that has not been dechlorinated first — why does this go wrong? — Changing too much water at once, with too great a temperature difference, and using tap water that has not been dechlorinated first. Many people assume the more water you change the cleaner it is, but changing more than half at once instead subjects the fish and shrimp to a violent water-quality and temperature shock and kills them outright. The chlorine in tap water is there to kill bacteria, and it is just as corrosive to fish gills, so it must always be treated before a water change.

Overfeeding — why does this go wrong?

Overfeeding. Fish and shrimp actually need far less food than you think, and uneaten food that sinks to the bottom of the tank and rots is manufacturing toxins. "The fish look eager to eat" does not mean they are hungry, and most aquarium deaths come from tanks ruined by overfeeding.

与えすぎ——なぜこれで問題が起きるのですか。 — 与えすぎ。 魚やエビが本当に必要とする量は、あなたが思うよりずっと少ないものです。食べ残した餌が底に沈んで腐れば、それは毒を作っているのと同じです。「魚が食べたそうにしている」ことは空腹を意味しません。死んでしまう水槽の多くは、与えすぎによって壊れています。

Overfeeding — why does this go wrong? — Overfeeding. Fish and shrimp actually need far less food than you think, and uneaten food that sinks to the bottom of the tank and rots is manufacturing toxins. "The fish look eager to eat" does not mean they are hungry, and most aquarium deaths come from tanks ruined by overfeeding.