Although most people think of saltwater when they think about tropical fish, there are many tropical fish that thrive in freshwater, too. If you're looking to create a freshwater aquarium, tropical fish can make it bright and vibrant. Knowing which rocks are best to put in the tank with these fish is important. Here's a look at what you need to know to avoid releasing harmful minerals into the water while still giving your fish rocks to swim around and make part of the habitat.
Slate is an ideal stone for freshwater aquariums because it doesn't release any chemicals into the water. It's pretty heavy, which means that if you plan to build a structure of any kind, you'll need an aquarium-quality sealant to keep it together. It's best to use it solely for tank-bottom decorations so that it can sit flat on the bottom of the tank. When you use it this way, the smooth texture of the slate surface provides an ideal environment for fish to nest and lay eggs..
Quartz stone makes a great addition for a freshwater tropical tank. The stone is inert, so it won't alter the tank chemistry at all. You can find it in many colors, which is ideal when you're putting it in a tropical tank because you can find colors that complement the fish you put into your tank. It's strong, stacks well and stays where you put it, so it's a good rock choice if you want to build any kind of stone structure in the tank.
Lava rock is wear-resistant and durable, making it great for a fish tank. It will hold up to the water and the typical chemistry of the system. The only thing to remember about lava rock is that it needs to be rinsed completely before it goes into the tank. Also, it's porous, making it great for filtering the water.
Sandstone is great for fish tanks because the earth tones blend well with the landscape. In addition, it's resistant to weathering. If you're not familiar with sandstone, it's a combination of things like quartz and feldspar. It's not good for structures, though. It's porous, which means that it won't hold up to the weight and pressure of being stacked.
With so many rock types that work well in freshwater tropical fish tanks, it's no surprise that new tank owners can be confused. The information here and your local tropical fish store, like Neptune's Tropical Fish, will help you find the rocks that fit what you need.