The rocks used in freshwater aquariums are often chosen not only for their appearance, but also for the caves, cavities, and structures that can be created from them. Fish like to have places like that to hide in, and they often seek out areas like that to lay eggs. Not to mention, the rock structures typically grow a thin algae cover that's a great food source for the scavengers in the tank. If you're new to having an aquarium, you may not know what's best to use in your tank. To avoid any potential problems, look for rocks like the following.
When you're looking for rocks that add an aesthetic quality without concern about the structural integrity, there are a couple of different options available.
- Slate - Slate rock is ideal for freshwater tanks because it's inert, which means that there's no risk of any kind of chemicals seeping into the water or contaminating the tank. The smooth surface of slate makes an ideal surface for fish eggs. In addition, they're heavy enough to sit securely in the bottom of the tank.
- Sandstone - Sandstone's composition makes it unique because it's made of a variety of sand grains and minerals. In fact, most sandstone has a combination of things like quartz and feldspar. The varying composition leads to many different colors and styles, although it's primarily available in shades of brown, red and tan. The durability of sandstone means it will hold up to a freshwater tank environment. It's not ideal for structures because it's porous, which can render it a bit unstable.
If you're looking for rocks that you can use to build wall structures, caves and other little hideaways and obstacles for the fish to swim through, you'll want to choose rocks that can stand up to being stacked. There are two common ones to consider.
- Quartz - Quartz is a great choice for structures, because it's heavy and non-porous, making it stable enough for building with. Quartz is another inert stone, so it isn't going to affect your tank's water chemistry. You can find a variety of smoky colors as well as some rose hues.
- Lava - Lava rock is popular for fish tanks because it's resistant to wear and lasts a long time. You just need to rinse or soak it thoroughly before you put it in the tank, because there's likely to be some sediment left on it. Soaking or rinsing it gets rid of that sediment so that it doesn't disperse into the tank water.
Before you build your aquarium, talk with a local fish tank and tropical fish supplier for help. With their guidance and the information here, you can choose the best stones for your tank and fish. For more information, consider contacting companies like Neptune's Tropical Fish.