How To Clean Fish Tank Gravel & Sand With Or Without A Vacuum

    How to clean fish tank gravel and sand

    The substrate of your tank may look simple. But it is the foundation to a healthy aquarium ecosystem. Plants, bacteria, and even fish make their homes here. So just how to clean fish tank gravel and sand?

    If you’re looking to perform regular maintenance then you will need a gravel vacuum. By plunging it into the substrate, you will remove embedded debris that lowers water quality if left to decay.

    Gravel and sand can also be removed for cleaning using bleach or vinegar. As well as scrubbed by hand to remove fine dust.

    Here are a few tips on how to maintain a good looking aquarium sand or gravel bottom!

    How To Clean Fish Tank Gravel With A Vacuum

    How to clean fish tank gravel
    Spotted silver dollar (Metynnis lippincottianus)

    Cleaning your fish tank substrate using gravel vacuums is a basic chore everyone should master. Doing so helps keep the tank healthy and attractive looking!

    You will need the following tools for gravel and sand cleaning:

    A gravel vacuum is the best tool for cleaning fish tank substrates. It penetrates deep beneath the grains. Pulling bits of fish waste, leftover food, and other decaying matter out. A gravel siphon allows you to clean the gravel while draining the tank.

    Step 1: Place the towels along the floor to prevent spills from making a mess. Newspaper pages are useful for cleaning up drips on the aquarium glass without leaving streaks. But towels do almost as good a job if you don’t have newspaper handy.

    Step 2: Remove the aquarium lid and turn off the filter and heater. We don’t want any technology running while removing water from the tank.

    If the water level gets too low, the filter may shut off. Power filters use pumps that are water-cooled. They can burn out if run without fresh water coming in.

    Heaters also depend on water to remain cool. A glass heater can overheat, cracking from temperature shock if splashed while hot.

    Step 3: Prime the gravel vacuum by filling the tube with water. The main siphon tube is gravity-powered, so you’ll need to follow a precise set of steps to initiate water flow. This video does a great job of breaking down the steps if you haven’t used one before!

    YouTube player

    Step 4: Plunge the gravel vacuum into the substrate. Dirty water full of debris will start to rise into the tube. Don’t allow too much gravel to enter the siphon. It will block water flow or even get sucked out of the tank if the grains are very small.

    Step 5: Remove as much water as needed to get the tank clean. If you are doing a regular water change then pull the siphon hose out at 20-30% of the tank’s volume. If you want to remove all of the gravel for cleaning, then continue siphoning out the tank water until it is empty.

    Step 6: Once you’ve emptied the tank, scoop out the aquarium gravel using the hand scoop. Only use plastic scoops; metal ones will scratch your aquarium glass. Or even crack it if dropped or otherwise impacted too suddenly.

    Step 7: Soak your gravel in a cleaning solution if it is stained with algae, bacteria, or other debris. I recommend soaking it for 24 hours in a 5% solution of bleach, using 3/4 cup of bleach in a gallon of water.

    Once 24 hours is up, rinse the gravel thoroughly, and then soak it for another 24 hours in a bucket of water treated with a generous dose of water conditioner. Both chlorine and bleach are detoxified by water conditioner.

    Step 8: Scrub the aquarium gravel using a high pressure water source. Then return it to your aquarium and refill the fish tank!

    How To Clean Fish Tank Sand With A Vacuum

    Cleaning fish tank sand with a vacuum is performed the same was as with gravel. The only difference is that you don’t want to allow much of the sand to enter the gravel siphon.

    Sand grains are much lighter than gravel grains. If the sand grains get high enough into the siphon they will get pulled into the bucket. Aquarium sand rarely needs a deep cleaning because it is packed so tightly. Most debris sits right on the surface.

    Sand is therefore faster and easier to clean than gravel. The downside to this is that sand will look dirty relatively fast. Unlike gravel, where debris is hidden between the larger grains for a while.

    How To Clean Fish Tank Gravel & Sand By Hand (Without A Vacuum)

    How to clean fish tank sand without a vacuum
    Weather spined loach (Cobitis taenia)

    You have to clean gravel and dry sand before adding it to your fish tank. Any new aquarium substrate is full of fine dust. This dirt will stay suspended in your water for a long time if not rinsed out.

    To clean fish tank sand or gravel by hand, pour the sand into a bucket. And then fill the bucket with tap water. Run your hands through the sand, stirring it to bring up the dust it contains.

    Pour off the dusty water and then refill with clean, cold water. Continue to stir and refill the bucket until the water runs clear and shows no cloudiness from dirt.

    This process can take awhile. Inorganic sand takes just a few minutes to rinse clean. But clay based substrates for live plants will take several rinse cycles to remove all of the dust.

    How To Clean Fish Tank Gravel With Vinegar

    Cleaning fish tank gravel with vinegar is something you will almost never do. Some websites promote cleaning aquarium sand and gravel once per year. Or even a few times per year.

    They suggest taking out all of your aquarium gravel and rinsing it is good. In reality, you should never empty your fish tank of gravel.

    Your gravel is where many of your beneficial bacteria live. These bacteria are essential to the aquarium nitrogen cycle. They consume the ammonia your fish release, breaking it down into nitrite. And then a step further into nitrate.

    Bacteria also live in the the filter of your fish tanks. But scrubbing your substrate for a clean sand look is not good for your fish.

    The only time you should remove and soak your aquarium sand is when you are buying a used tank. If you want to re-use the old substrate then the dirty sand needs to be scrubbed.

    You never know what sort of parasites, bacteria, or rotting organic matter is still trapped in it.

    Here are the materials needed for cleaning aquarium sand with vinegar:

    The old aquarium sand needs to be removed from the tank into a large bucket. Or several buckets; the sand layer should not go much deeper than a few inches.

    For one, aquarium sand is very heavy. And two, we want the sand substrate to remain in a thin layer so it can be stirred with ease.

    Add 1 cup of vinegar and 4 cups of water to the old aquarium sand. Then run your hands through the sand substrate, ensuring the solution penetrates thoroughly.

    Allow freshwater aquarium sand to soak in the vinegar solution for up to 24 hours. Soak for no longer than an hour if using coral sand for saltwater tanks. Marine reef sand is made of calcium carbonate, which is reactive with vinegar.

    Last, get the sand clean by rinsing it thoroughly before adding to your new aquarium! I recommend using a garden hose or faucet with a powerful outflow.

    Strong water pressure will stir up light sand particles and dust. Ensuring your aquarium water remains clear as you fill the fish tank.

    How Often Should You Clean Fish Tank Gravel?

    How often should you clean fish tank gravel
    Tubenose goby (Proterorhinus semilunaris)

    I recommend cleaning your fish tank gravel at most once per year. The process eliminates all of the beneficial bacteria that live in your substrate. Which can partially reset the aquarium nitrogen cycle.

    Only do deep gravel cleans if there is no other way to control the buildup of debris. Brown algae, green algae, muck, biofilm… All of these can be managed or eliminated using light and nutrient flow management instead.

    The best time to clean your aquarium gravel is right before adding it to the tank for the first time. Most local aquarium store products are full of fine dust. Rinsing it beforehand will

    The gravel cleaning process is a time consuming job. If you want to extend the amount of time between cleanings, try using a bacterial additive.

    Natural Rapport Aquarium Gravel Cleaner adds beneficial bacteria that eat fish waste, poop, biofilm, and other debris. Keeping your aquarium clean for a longer period.

    This gravel cleaner even reduces ammonia, nitrite, and nitrate levels in the process! That said, no product will fully eliminate a water change or occasional gravel clean.

    How Often Should You Clean Fish Tank Sand?

    Like gravel, you don’t want to completely scrub your fish tank sand all that often. Healthy sand has rich microbial life within it.

    Those microbes may turn your sand slightly dark. But they more than make up for it by feeding on ammonia and other pollutants.

    Brand new sand tends to have more dirt and debris than gravel does. Therefore, it’s even more important to rinse sand before using it as tank décor. Un-rinsed sand will release a plume of dust that can severely irritate fish gills.

    This dirt does settle out of the water eventually. But any sort of sudden movements from fish will cause a dust cloud to kick right back up again.

    Freshwater Bottom Feeder Fish & Invertebrates That Clean Gravel & Sand

    The gravel and sand surface is not nearly as important as the region underneath. Water flow in most aquariums is not strong enough to force currents into a packed sand bottom.

    So if you have a deep sand substrate, it needs aquatic life to penetrate it. Otherwise, you get dead zones with no oxygen (anoxic).

    Anoxic zones occur when organic matter decays without oxygen around. Anaerobic bacteria that thrive where oxygen is absent create hydrogen sulfide and other highly poisonous byproducts.

    Sometimes these gases sit in bubbles that collect over time. Releasing suddenly as a toxic, foul-smelling “burp” that is dangerous to all aquatic animal life.

    Kuhli Loach

    If you have a tank with an aquarium sand substrate, it’s hard not to resist kuhli loaches (Pangio kuhlii). These colorful small loaches have a worm-like body that enables them to thread their way through tangled plant roots.

    Kuhli loaches will also bury themselves entirely in the sand to sniff out and find food. It can make finding them a chore since they will bury themselves for days at a time. But when they get hungry kuhli loaches are active, eager eaters!

    By burrowing through aquarium sand kuhli loaches ensure all the sand is penetrated by oxygen-rich water. This prevents dead, anoxic pockets from forming.

    Corydoras Catfish

    Corydoras catfish are some of my favorite bottom feeding sand sifters. Cories are an entire genus of freshwater catfish from South America. They range in size from pygmy corydoras at less than 1 inch. All the way to the 4 inch brochis cories.

    All of them are peaceful, schooling fish species. Cories do need soft, acidic water conditions and tropical temperatures of 73-83°F to thrive. They are carnivorous fish, feeding on small worms, insect larvae, and other invertebrates.

    Corydoras catfish root around in the substrate for food using their snout-like mouths and sensitive whiskers. Clean aquarium sand is the best substrate for cories as gravel grains can scratch their snouts. Or even cause their whiskers to break off.

    Malaysian Trumpet Snails

    Malaysian trumpet snails (Melanoides tuberculata) are small detritivores, feeding on algae and leftover food. They have pretty curved shells and don’t grow larger than an inch long.

    Trumpet snails are burrowers and spend most of their time trying to push through the substrate. When they smell hidden food they converge onto it, eating it before it decays into ammonia.

    The main downside to keeping trumpet snails is that they have a tendency to reproduce out of control. These snails are livebearers and will have up to 70 babies at a time.

    Fortunately, I discuss several control strategies in my guide on How To Get Rid Of Snails In A Fish Tank!

    Saltwater Bottom Feeder Fish & Invertebrates That Clean Gravel & Sand

    Diamond watchman goby (Valenciennea puellaris)

    Anoxic pockets are just as dangerous to saltwater aquarium keepers. Fortunately, there are even more fish species and invertebrates that will ensure your sand has good water flow. And remains highly oxygenated!

    Diamond Watchman Goby

    The diamond watchman goby (Valenciennea puellaris) is an excellent sand sifting bottom dweller for aquariums 30 gallons or larger. They reach up to 6 inches in length. Diamond watchman gobies clean sand while hunting for morsels of hidden food. They take a large mouthful and pass it through their gills.

    Keeping sand is essential for a tank with a diamond goby. As they settle in, the goby will dig a small tunnel under a piece of live rock. Gravel grains are too large for them to sift or dig through. Stick with a fine sand substrate that is 4 inches deep or more!

    Brittle Starfish

    Brittle starfish often find their way into a reef tank as live rock hitch hikers. There are dozens of different species that vary in size. A few grow impressively large but most are just a few inches across. All are excellent sand sifting animals to keep.

    Brittle starfish are mostly nocturnal. Once your aquarium lights go out they leave their hiding places. Some prefer hiding in rocky crevices while others burrow into the substrate.

    Their long arms are packed with sensory organs to sniff out decaying food. Brittle starfish find and eat leftovers before they have a chance to raise ammonia and nitrite levels.

    Cerith Snail

    Cerith snails (Cerithium sp.) are inch-long sand sifting invertebrates from the Caribbean Sea. They are inexpensive additions to any reef or fish-only aquarium.

    Cerith snails are strong enough to burrow through both aquarium sand and gravel. Hunting down any organic matter and eating it before it decays.

    Add one or two cerith snails per gallon of aquarium volume to get your saltwater clean-up crew started. Besides detritus, they also eat green algae, brown algae, and even blue-green algae.

    Nassarius Snail

    Nassarius snails (Nassarius sp.) are similar in care to cerith snails. Except most of the species in this group are carnivorous scavenging snails. So don’t expect them to do much to your algae growth.

    Nassarius snails prefer to stay buried under your aquarium sand with just their siphon sticking out. This allows them to not only breathe, but smell the water for food.

    Once they smell the rot of a dead animal or leftover food, they rise out of the sand. Often all at the same time. Hence their other common name of “zombie snail!”


    Choosing the right aquarium sand and gravel is only the first step in beautifying your tank. You now have to keep gravel and sand clean.

    Fish and invertebrates can help by aerating it and eating leftovers hidden inside. But you’ll still need to lend a hand by putting to use the top tips I’ve outlined above!

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