1. What is Cultured Gravel?
is normal aquarium gravel with a layer of beneficial bacteria growing on the surface of the pieces of gravel.

You can buy normal aquarium gravel in most stores that sell pet fish. But new gravel in the bag will not be cultured. Sometimes a fish store will sell you a handful of cultured gravel from one of their aquariums. 

Fish bowls need a layer of cultured gravel about 1/4-inch thick, so the bacteria living on the gravel can biologically remove waste from the water in the fish bowl.

But an aquarium with a power filter and a BIO-Wheel does not need gravel, because the beneficial bacteria grow abundantly on the BIO-Wheel.

A layer of gravel, that is more than 1/4-inch thick, often gets full of uneaten food and causes pollution problems. So don't have a layer of gravel more than 1/4-inch thick in your freshwater aquarium or in your fish bowl.

If you are a beginner with your first aquarium, be sure you get a filter with a BIO-Wheel and don't put any gravel in your aquarium.

If you like the appearance of gravel, and you've mastered feeding your fish so there are no uneaten bits of fish food to pollute the gravel, then add a thin layer of gravel not more than 1/4-inch thick.

If you decide to have gravel in your aquarium, use your net to stir it gently to see if the gravel is full of waste. If it is, then you need to immediately clean your gravel. Click here for more information about cleaning gravel. In the future be sure your fish eat all the food you feed them. Click here for more information about feeding fish.

2. Safe Gravel
Not all gravel is safe for fish. Some gravel may contain toxic minerals. So you should always buy gravel that is labeled for use in aquariums. Generally everything that goes into your aquarium should be labeled for use in aquariums.

Where can you get cultured gravel for your fish bowl? We send a bag of cultured gravel with each of our Fish Bowl Kits. Alternatively you could ask a friend, who has an aquarium with gravel or ask your local pet store for some gravel from one of their aquariums.

You only need a handful of cultured gravel to mix with your new gravel. The beneficial bacteria from the handful of cultured gravel will quickly grow and cover your new gravel.

If you have more than 1/4" of gravel, you should not stir the gravel. Instead wash the gravel with a Gravel Vacuum. Don't get the kind of gravel washer with a bag that puts the water back in the aquarium.