Freshwater Tank Care Articles Read some of the more than 100 freshwater tank care tips here from expert fishkeepers so you can apply what they know to your successful aquarium endeavors. These are tried and true tips that will keep your tank and its inhabitants healthy. Fish Fungus and Scale Problems Fungal infections are often the result of other diseases caused by poor water quality. Aquarium Fish and Fungus Fungal infections are often the result of other diseases caused by poor water quality. Follow the Clues in Your Tank Follow the clues your tank is giving you to discover any problems. How High Summer Temperatures Affect Your Aquarium The difficulty is not in the fishes’ inability to withstand the temperature, but rather in the side effects of the higher temperatures. Determining Goldfish Growth The rate of growth is determined by the aquatic environment. Freshwater Forum: Euthanizing Fish Learn how to euthanize and spawn fish. Aquarium Filter Maintenance Aquarium filter types and maintenance. Sponge Filters: The Portable Approach to Biological Filtration There are times when a sponge filter is a better choice than an undergravel filter. Canister Filters How they work and what to look for. Aquarium Carbon Most aquarists have used aquarium carbon at some point — but how exactly does it do its job?