SAND OR GRAVEL

Why do we need a substrate

   Even though a sand or gravel substrate is not a must in a beginner's aquarium, it is good to have this item in the tank. The sand or gravel not only adds attraction to the tank, but also can act as an anchor for the roots of some plants. The fish also do not like to see a transparent bottom or reflective bottom. The gravel would provide fishes a more natural home.

Type of substrates

  The best type of sand or gravel is the smooth and round pebbles of 3 to 5 mm diameter. The type of gravel shall preferably be from a river bed although other types are also acceptable. Calcium rich rocks should be avoided as these would change the pH of water very soon and the fishes will have problem coping with the hard water. The gravel should not be too fine as this would result in cleaning problems. Very fine grade of sand can cause problems to your under gravel filter sometimes. If the pebbles have rough and sharp edges then the fishes might get injured while trying to pick up some food from the bottom. Some fishes love to burrow into the substrate either for food or for laying eggs or just for resting. In such cases care should be taken to provide smooth edged gravel. Also some fishes such as gold fish have the habit of taking the stones into their mouth and then spitting them out later. If the edges are sharp they may get hurt. The well rounded gravel can be easily bought from garden accessories shop or shops selling plants and potting material. The gravel should be washed thoroughly using hot water and then put into the tank. For tanks where you want to keep hard water species, you can used crushed coral as substrate, which can help keep your pH/dH high.

   If you are using gravel or rocks collected by yourself, check if it will affect the water hardness. Drop a few droplets of pH down on the rocks. If you see any fizzing or bubbles, the gravel/rocks are alkaline and will not be safe for your tank. Commercial acid can also be used for testing but you have to be careful about handling such stuff. pH down is preferable and safe. Calcitic rocks and gravel can be benficial to some cichlid tanks where water hardness is important.

Sea Chem -Fluorite

Sea Chem -Sand substrate

Sea Chem -Fluorite red

   Some of the commercially available substrate materials are shown above. But in my opinion you can buy a simple gravel, crushed marble or crused coral at your nearby shop selling gardening stuff. Make sure you wash as per set up procedure described else where. Some types of commercial gravel available is shown below. These are not under any brand names and you can find them in many gardening supplies shop. But remember that for growing plants simple gravel is not enough for many plants.

Gravel

White Gravel

Black gravel