Aquarium Gravel

There are several reason why we use gravel in aquarium. Aquarium gravel is beneficial  because it provides decoration, a way to anchor plants or other decorations and also serves as a biological filtration system.

Decoration

The gravel layer will give a terrific visual effect especially combined with some lightning effect.    A bare tank with no gravel may look drab and look less attractive. Because gravel comes in multiple colors and textures, it is easy to find gravel that will match the vibe you want from the fish tank.A fish tank with gravel is pleasing aesthetically and gives the aquarium a more natural feel.


Biological Filtration

Perhaps the most crucial benefit of gravel is that it provides a biological filtration system. Gravel layer serves a very large surface area for beneficial bacteria colonization.

Anchor for plants and other decoration

If you plan to grow plants, you will need something to anchor them down in. A 1-inch layer of gravel along the bottom of the aquarium will allow for enough gravel to support the weight of any plants. Also, some decorations need to be anchored down to prevent floating or being turned over easily. Gravel works to anchor plants and decorations so that the tank can hold the items you want it to hold.

Not all kind of gravel is suitable to use in aquarium although the color and shape is highly beautiful. The limitation comes from the fact that certain rocks will alter the water parameter. Some  rockst are highly calcareous – meaning they have a large amount of calcium which will alter the hardness and pH of  the water. This can be hazardous to the living inside the aquarium.

Rocks to Avoid include:

• Limestone
  
• Marble
  
• Geodes
  
• Dolomite
  
• Shells or crushed coral

Safer Rocks Include:

• Granite
• Quartz
  
• Slate
  
• Lava Rock
  
• Onyx
  
• Sandstone (should always test before using)

It is always best to test the gravel first before applying it to the tanks. Simple testing can be done using vinegar. Place a few drops of vinegar on the rock or gravel you are considering using. If it fizzes or foams, don't use it, as it contains calcium deposits. Another way of testing rocks and gravel is to place them in a bucket of the same water that you use in your aquarium. Test the pH and hardness before, and then let it sit for a week and test again. If there is a significant change, the rocks or gravel are likely to cause problems.

Generally gravel that are sold in the petstore are safe for aquarium use. But it won't hurt to test prior using them as not all aquarium suppliers understand about  this point.

Gravel should cover the aquarium bottom  of  approximately 3 inches deep.

Another important thing in setting up aquarium with gravel is to wash the gravel thoroughly before use.