Frequently asked questions

Freshwater Care

What does "NO2-N" mean?

Hello, this is nitrite nitrogen, or in other words the N that is included in NO2. Correspondingly, both values (NO2 and NO2-N) can be converted into each other by simply multiplying...

Freshwater Care Technical equipment

Which CO2 unit for a 60 cm (23.6 in.) aquarium?

Hello, our sera CO2-Start with the corresponding sera CO2-Tabs plus is ideal for aquariums of this size - this system has been developed precisely for this kind of use! Best regards...

Freshwater Food Fish

Which food is suitable for Ancistrus catfish, Platies and Mollies?

Hello, in particular, sera Catfish Chips, sera Spirulina Tabs and sera Viformo are suitable for the catfish. sera Flora, sera GVG-Mix, sera Spirulina Tabs (attached to the aquarium...


Which size for a beginner's tank?

Hello, the general rule is: the bigger, the better. Most aquarists start with a 60 cm (23.6 in.) or 60 liter (13.2 US gal.) tank, which is fine for many small fish and shrimps, but...

Freshwater Diseases

White spots on the fish?

Hello, white spots are almost always a symptom of Ichthyophthirius multifiliis, often simply called "Ich", one of the most frequent fish diseases in aquariums. The disease is very...

Freshwater Invertebrates

Worms and Hydra

Hello, Concerning "flalworms/Hydra":flatworms are one possibility considering the animals that creep on the glass pane, however threadworms (nematodes) or oligochaetes are also...

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