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How to Use a Gravel Vacuum to Clean Aquariums

Ever wonder if there’s an easy way to clean all the fish waste and uneaten food that’s fallen in between the aquarium’s gravel or substrate? The good news is that there’s no need to dump out and wash everything in the sink. Instead, you can vacuum up the detritus with a simple aquarium siphon – no batteries required!

Step 1: Get the Materials

You just need two items: an aquarium siphon (also known as a gravel vacuum, gravel cleaner, or siphon kit) and a bucket to hold the dirty water. If you plan on cleaning multiple tanks, it might be easier to get a large trash can on wheels to put the dirty water. However, the bucket is optional if your siphon’s hose is long enough to reach a nearby sink or even the backyard to water your outdoor plants.

siphon diagram

A siphon basically consists of two sections: the plastic tube that goes into the aquarium and the long, flexible hose that goes into the bucket.

We personally like using the Python Pro-Clean siphon because its high-quality, flexible tubing doesn’t kink or get twisted as easily. (As an Amazon Associate, we earn from qualifying purchases, and commissions may be earned from the link above.)

Step 2: Prepare the Tank

There is no need to remove the fish while using the aquarium siphon, since the process of catching them is more stressful than slowly vacuuming around them. However, you should move any aquarium decorations away from the area you plan on vacuuming because waste likes to collect underneath them. Some people like to scrub off the algae and clean the filter beforehand, so that all the excess particles in the water have a chance of being removed by the siphon.

Mag-Float algae scrapersMagnetic algae scrappers are great for cleaning off algae, especially if you have the matching blade attachment. Just make sure to get the glass or acrylic version that matches your aquarium walls. 

Step 3: Start the Siphon

Aquarium siphons use gravity to suck the water and debris out of your aquarium. To start the siphon, make sure the hose end of the siphon is inside the bucket. (Some people use a small clamp to make sure the hose doesn’t slip out of the bucket.) Then completely submerge the tube inside the aquarium so that it fills with water. You can easily do this by keeping the tube at a diagonal angle with the tube opening pointed upwards.

Submerge the tube


Raise the tube out of the water and above the aquarium rim until water starts flowing through the hose and into the bucket.

Raise the tube


As soon as the water has drained halfway out of the tube, quickly plunge the tube back into the water at the same diagonal angle (such that the tube is still pointed upwards). The tube opening must be completely underwater in order for the water to continue draining into the bucket.

Plunge tube back in


Once water is freely flowing into the bucket, point the tube opening downwards toward the substrate at the bottom of the tank.

Point tube toward gravel


Note: if the water level is too low or the tank is too small to maneuver the tube using this technique, you may need to use another method to start the siphon. The easiest method is to place the tube end in the aquarium and suck on the hose end with your mouth to get water flowing through it. Quickly place the hose end into the bucket, or else you may get a mouthful of dirty fish water. 

Step 4: Vacuum the Gravel

Push the siphon into the gravel or sand, and let it start vacuuming up some of the substrate. Because the substrate is heavier than the fish waste, you can periodically crimp the hose with your other hand that’s not in the water to briefly stop the suction. This causes the heavy substrate to fall out of the tube, while the lighter debris still floats inside the tube and gets sucked up as soon as you un-crimp the hose and start vacuuming again.

Crimp the hose


Systematically vacuum the substrate back and forth in rows, as if you’re mowing the lawn. Use this method to clean about a third of the aquarium substrate.  The next time you do a water change, you can vacuum the next third of the tank.

Step 5: Remove the Siphon

Once you’re ready to stop siphoning, cover the tube opening with your hand and lift the tube out. The tube will suction to your hand and prevent the dirty water from falling back into the aquarium. Flip the tube upwards and let the remaining water in the siphon drain into the bucket.

Remove the siphon


If you're still not able to start the siphon, click on the video demonstration below to watch this simple process in action:

Thumbnail with play button for siphon video


And that’s it! Refill the aquarium with new water that’s roughly the same temperature as the old water, and don’t forget to add dechlorinator to remove the chlorine, chloramine, and other toxic chemicals from the water. 

Bonus Tip: Fill the Tank Without a Bucket

If you want to fill your fish tank (or multiple tanks) straight from the sink faucet without having to lug buckets of water back and forth, all you need is a garden hose, faucet hose adaptor, and the Python hook. 

  1. Unscrew the sink faucet aerator from the faucet opening. Screw on the faucet hose adaptor that has a 3/4" male garden hose connection. (If you cannot find an adapter that fits your faucet, take the sink aerator to the hardware store to get help finding the right adaptor.) 
  1. Attach one end of the garden hose to the sink adapter. Attach the other end of the garden hose to the Python hook.
Python hook for aquariums

Python hook

  1. Hang the Python hook on the aquarium wall to ensure that the garden hose will not slip out of the tank while filling it.
  2. Turn on the sink to the right temperature, and start the water flowing directly into your fish tank. 
  3. Once your aquarium is full, turn off the sink water. If you are done with all your water changes, raise the Python hook higher than the sink, and let the remaining water in the hose flow back into the sink drain as you coil the hose for storage.

To find out how often you need to do water changes on your aquarium, download our free infographic that guides you step-by-step through the process.

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