How to Clean Aquarium Gravel

Getting Started

Unplug the heater, filter, and pump. Before you do anything to your tank, you must unplug the heater and turn off the filter and pump. Don't worry, the cleaning process is quick, so your fish will be fine. Do not remove your fish, decorations, or plants from the tank.

Get out your aquarium vacuum. There are two tools aquarium hobbyists will use for cleaning their gravel. Aquarium siphons usually have a thick, plastic tube or "siphon" with a thin, flexible, tube attached to one end. Some of these may have a priming ball attached to one end. Plastic, flexible tubes can also be used to clean gravel. These are ideal for smaller tanks.

Place a bucket below the aquarium. The bucket must be beneath the water level. It will catch the old water.

Start the vacuum by submerging it. Slowly lower the entire siphon into the tank so that all of the air gets out of the tube. Cover the end of the tube with your thumb and take it out of the tank; keep the other, open, end submerged. Place the covered end in a bucket. If you release your thumb, the water will begin to flow; if you cover the end again with your thumb, the water will stop.

Start the vacuum with a priming ball. Some aquarium vacuums come with a rubber ball attached to the end of the siphon. Stick the end of the siphon into the aquarium and lower the end of the tube into a bucket. Plug the end of the tube with your finger, and squeeze on the priming ball. Slowly let go of the ball, but keep the end of the tube plugged. Water will begin to fill the siphon, sort of like an eyedropper or turkey baster. When you unplug the end of the tube, water will start to flow into the bucket.

Know how to start up a Python, and other similar types of vacuums, if you are using one. These types of gravel vacuums are different from all others. They do not require a bucket. Instead, they need to be hooked up to a water faucet. Simply plug the end of the Python vacuum to your water faucet and place the entire vacuum into the aquarium. When you turn the faucet on, the vacuum will begin to siphon.

Vacuuming the Gravel

Place the end of the vacuum into the gravel. Simply stick it straight down, as far as it will go. Your thumb should still be blocking the end of the tube, and that the end of the tube is in the bucket. Once you let go of the tube, dirty water will start flowing out. If you have very fine-grit gravel, such as sand, don't stick the vacuum all the way down. Instead, place the mouth just over the top of the sand. Vacuuming is okay for freshwater tanks, but it's not a great option for saltwater aquariums, especially ones with sand. If you use a vacuum in a saltwater tank, you'll end up disturbing the bacteria in the sand and destroying your tank's micro-ecosystem. Only vacuum a saltwater tank if you've got some crushed coral along with some, big predatory fish. In that case, vacuum every few months to clean up the build-up.

Let go of the tube. With the end of the tube still in the bucket, slowly pull your thumb away from the end of the tube. This will start creating the siphoning effect. Dirty water will flow out of the end of the tube and into the bucket. The gravel will shake and rattle inside the tube. If you are using a Python, or a similar type, simply turn the water on the begin siphoning.

Cover the end of the tube once the water starts to run clear. How long this takes will depend on how dirty your aquarium is to begin with. When you recover the tube, the gravel will settle once again. If the gravel starts to go too far up the vacuum, just cover the end of the tube and let the gravel settle. Then, uncover the tube and let the water flow again. If you are using a Python, or a similar type, simply turn the water off the stop siphoning.

Remove the vacuum from the gravel, but not out of the water. Try to keep it as straight as possible, so that you don't dislodge the adjacent debris.

Move the vacuum to the next patch of dirty gravel and repeat the process. Push the vacuum straight down into the gravel, and slowly release the end of the tube. When the water runs clear again, cover the tube back up and carefully lift the vacuum out. If your tank has any caves, rocks, logs, and other nooks and crannies, be sure to give those special attention. These areas tend to get the most waste. If your tank has any live plants, leave a 2 inch (5.08 centimeters) radius around the stems. Plants love organic waste. If you remove this waste, the plants won't have anything to eat.

Do not clean all of the gravel. Keep vacuuming until the water level is two-thirds of the way full. By now, you will have cleaned one-fourth to one-third of the gravel. This is perfectly fine. You do not want to clean more than that at one time. Aquarium gravel hosts a lot of good, helpful bacteria that is important for the health of your tank. You can continue cleaning the gravel the next time you do a partial water change.

Finishing Up

Take the temperature of the tank's water. You have just removed a lot of dirty water, and you will need to replace it. Fish are very sensitive to water changes, so the new water will have to be the same temperature as the old. Most tanks should have a thermometer, but if yours doesn't, you'll need to stick a clean, glass thermometer into the water.

Fill a clean bucket with water that is the same temperature as your tank's water. Make sure that the bucket never came to contact with any chemicals or cleaners. Any residue left behind can be extremely deadly for your fish. Fill the bucket with water that is the same

Treat the water, if necessary. Most tap water is not aquarium safe. Use any necessary water conditioners to remove chlorine and other harmful chemicals. You can buy these from an aquarium store or in the aquatics department of a pet store.

Place the bucket above the water level of the aquarium. You will be reverse siphoning the water back into the tank. The bucket must be above the water level, or the water will not siphon back properly. Simply pouring the water back in might seem easier, but this can cause debris to rise up and cloud the water.

Stick the entire rubber tube into the tank and plug on end up with your finger. If you are using a gravel vacuum with a plastic siphon, see if you can pop the flexible tube off.

Leave the uncovered end in the bucket and place the covered end in the tank. Slowly let go of the tube. The water should start flowing back into the tank.

Remove the tube from the tank when the water level is about 1 inch (2.54 centimeters) away from the top edge. This space is important. Fish need oxygen, and if you don't leave that space, the water won't get enough oxygen for your fish.

Re-plug the heater, filter, and pump. Once your aquarium is all set up again, plug the heater back in, and restart the filter and pump. Take note of when you cleaned your tank, and make a note on your calendar for the next cleaning date.

Cleaning Store-bought Gravel

Only clean gravel before putting it into your tank for the first time. This is the only time you should be cleaning the gravel. Once your gravel is in the tank, you should only vacuum it. Gravel hosts a lot of good, helpful bacteria that are beneficial for your aquarium. Rinsing your gravel will get rid of that bacteria.

Open up the bag that your gravel came in. Store-bought gravel must be cleaned. It often contains dust and dirt that can be harmful to your fish. If you picked your gravel up from elsewhere, you will want to clean it as well.

Get a colander or mesh strainer. The smaller your gravel is, the tighter the weave you will need. Make sure that you are not using this colander or strainer for any other purpose. Also, make sure that the colander/strainer never came into contact with soap or other detergents. If you are cleaning sand, consider using a piece of cotton instead.

Fill the colander or strainer with gravel. If you have a lot of gravel to clean, you may need to work in smaller batches. The gravel should enough room in the colander/strainer to move around without spilling over the edges.

Place the colander/strainer into a sink and turn on the water. Use a warm or hot water setting. This will help kill any bacteria. Do 'not add any soap, detergent, or bleach. Doing so can kill your fish.

Move the gravel about until the water runs clear. Shake and jiggle the colander/strainer. Stick your hand into the gravel, and sift it about. Keep doing this until the water runs clear.

Transfer the gravel to your aquarium. Turn off the water and give the colander/strainer a final shake to get rid of any excess water. Spread the gravel along the bottom of your tank. If you still have more gravel to add, repeat the whole cleaning process for each batch.