How To Clean Fish Tank Glass – White Residue & Algae Removal

    How to clean fish tank glass inside and outside

    Dirty aquarium glass can make your setup look unsightly and make it difficult to see your fish. That’s why it’s important to know how to clean fish tank glass the right way. You’ll get a lot more enjoyment out of your fish and make their habitat healthier overall!

    The best way to clean your fish tank glass is by using an algae scraper, clean sponges or cloths, and some distilled white vinegar. This will remove the majority of dirt and grime, including limescale and algae.

    If you’re looking for more information on how to clean your tank glass and keep it looking sparkling new, our guide will aid you through the entire process.

    How To Clean Fish Tank Glass Inside

    How to clean fish tank glass inside

    The best method for cleaning the inside of your aquarium glass depends on the severity of the limescale or algae buildup. For mild cases, you may only need a sponge to get rid of the residue.

    Deep stains, on the other hand, will usually need more drastic measures to remove. Distilled white vinegar is effective for keeping your aquarium glass clean.

    We’ll be going over how to clean inside glass and acrylic aquariums below, but this video also does a great job explaining the process:

    YouTube player

    Supplies Needed

    Cleaning inside your tank isn’t a complicated task, but you’ll need a few supplies to do it effectively.


    Once you have all the supplies you need, it’s time to start cleaning aquarium glass!

    Step 1:

    If there is only a bit of algae or debris on the inside of your tank glass, you may be able to remove it with just a clean sponge. Make sure you use new sponges that haven’t been contaminated with cleaning products.

    Wipe down the glass with the sponge using just tank water to see if you can dislodge it. You don’t need to relocate your tank inhabitants for this.

    Step 2:

    Severe algae or dirt buildup can be difficult to remove with just sponges. You may need to use an algae scraper or magnetic glass cleaner to eliminate all of it. Scrape all the sides of the tank with the scraper, and don’t forget the inner corners!

    If using a magnet cleaner, make sure the scrubbing pad side goes inside the tank. The handle part should go on the outside.

    Your fish can stay in the tank while you do this. Let the algae or dirt fall to the bottom of the tank substrate (gravel, sand, etc). You can then remove it with an aquarium vacuum cleaner or automatic cleaner. 

    If you don’t have an aquarium magnet cleaner or scraper, you can also use a razor blade for glass tanks. Acrylic tanks, however, will need to be cleaned with a plastic scraper or blade to prevent scratching.

    Step 3:

    For severe algae growth or stubborn dirt, you may need to use white vinegar to keep your tank glass clean. You will need to place your aquatic animals inside another tank with some old water for this procedure.

    Once you’ve moved your aquatic pets, remove the substrate, filter, heater, decor, etc. Keep the filter in a bucket of tank water so you don’t kill off your beneficial bacteria.

    Step 4:

    Drain the entire tank, then place the aquarium on its side on some microfiber towels. Pour a solution of white vinegar and water (one part vinegar and one part water) on the dirty side of the glass. Leave it to set for 10 to 20 minutes.

    Step 5:

    Using non-abrasive clean sponges or cloths, scrub the glass until it’s clean. Be careful when cleaning the joints of the tank – you don’t want to damage the silicone!

    Step 6:

    When you’ve finished cleaning your tank glass, rinse the tank thoroughly with clean water. Fill it back up with dechlorinated water and the rest of your decorations/equipment.

    How To Clean Fish Tank Glass Outside

    How to clean aquarium glass outside

    Hard water residue and limescale can build up on the outside of your tank glass, so it’s important to clean it from time to time. Ideally, you should be wiping down your tank glass every time you perform a water change.

    Supplies Needed

    Before you go ahead and clean the outside of your tank, make sure you have the following supplies:

    • Sponge
    • Distilled white vinegar or fish-safe cleaner spray
    • Microfiber cloths or paper towels


    Once you have all the supplies you need, follow the steps below to clean aquarium glass outside.

    Step 1:

    Using new sponges, scrub the outside surface of the tank with a bit of distilled white vinegar or a fish-safe cleaner. Mix one part water with one part vinegar.

    Don’t use household cleaning products as they usually contain chemicals that are toxic to aquatic life.

    Step 2:

    Wet some paper towels or microfiber cloths with some water, then wipe down the glass. You may need to do this a few times to polish the glass.

    Step 3:

    Using dry microfiber towels, soak up the excess liquid from the glass and buff it out. Your tank glass should now look crystal clear!

    How To Clean White Residue & Stains On Fish Tank Glass

    How To Clean White Residue & Stains On Fish Tank Glass

    A white residue forming on your tank glass can make your setup look untidy. It will also make it harder to look inside and view your aquatic pets. The white residue is known as limescale and is caused by calcium or mineral deposits in your water.

    Limescale is more likely to form in hard water as it contains a higher content of minerals like calcium and magnesium. It can be difficult to remove hard water stains from your glass, especially if they’ve been present for a while.

    However, with a bit of scrubbing and the right supplies, you’ll have your tank glass looking new again!

    Supplies Needed

    • Sponge
    • Distilled white vinegar or lemon juice
    • Microfiber cloths
    • Algae scraper
    • Holding tank


    Getting rid of limescale from your tank glass requires a little more effort than other types of grime, but it can be done using the method below.

    Step 1:

    Move your fish to a separate tank, then mix one part water with one part distilled white vinegar. Lemon juice can also work in a pinch, but distilled white vinegar is more effective at removing limescale.

    Step 2:

    Lay down some towels and place your tank on its side. Pour the solution over the affected area and let it sit for 10 to 20 minutes.

    Step 3:

    Use a new sponge to scrub the walls. You may need to use an algae scraper or a razor blade to dislodge particularly tough residue.

    As mentioned earlier, use plastic scrapers for acrylic fish tanks so you don’t scratch them!

    Step 4:

    Rinse the tank well with water, then go over the glass again with a microfiber cloth.

    How To Prevent White Residue & Stains On The Glass

    How To Prevent White Residue & Stains On Aquarium Glass

    White residue, also known as limescale, can be a pain to deal with in an aquarium. It can build up on the glass, as well as around your aquarium lights, filter, and heater. Fortunately, there are a few things you can do to prevent it from developing and keep your aquarium clean.

    Use Distilled Water

    Hard water contains a lot of minerals, which can lead to the formation of limescale once it evaporates. Warm temperatures and low humidity can increase the rate of evaporation in your tank, so you might notice more limescale during these times.

    Topping off your setup with distilled water can help prevent the buildup of limescale. As water evaporates in your tank, the leftover water will turn a little harder. This is because there will be a higher level of minerals in the water.

    Using distilled water to replace the evaporated water can help balance out the mineral density as it is completely pure.

    In addition, if you top off your tank water with more mineral-heavy water, it can gradually increase the level of certain minerals. This can be lethal, so distilled water is your safest option.

    When performing water changes, however, you can use regular dechlorinated tap water. This will maintain the level of minerals, keep the pH stable, and prevent acidification.

    Perform Regular Water Changes

    Performing frequent water changes can help you combat limescale buildup on the walls of your aquarium. As mentioned above, once water evaporates, any water left over will become harder.

    Keeping on top of your tank maintenance will help you stabilize the mineral levels in your water, as well as allow your aquatic pets to thrive. You should aim to do a partial (around 10 to 15%) water change every week.

    That said, if your aquarium is small and contains a lot of aquatic life, be careful as you may need to perform more frequent water changes.

    Clean The Aquarium Glass Frequently

    Even if your tank glass is free from limescale at the moment, it doesn’t hurt to wipe down the walls once a week to maintain its clarity. Use a magnetic aquarium glass cleaner, sponges, or scraper to gently scrape away any grime or residue.

    Be careful when cleaning an acrylic tank as they can be easily scratched by metal scrapers and razor blades.

    How To Remove Algae From Fish Tank Glass

    How to remove algae from aquarium glass

    Algae can be a real nuisance in your tank, especially when it starts to appear on your glass. It can obstruct the view of your fish and, in severe cases, make your water look green.

    Although algae itself isn’t harmful to aquatic life, it can be a sign that there isn’t something quite right with your setup. It’s important to identify the cause of the algae overgrowth and remove it promptly.

    Manually Remove It

    The quickest way to remove algae from your glass is to remove it using an aquarium magnet cleaner or scraper. Metal blades are ideal for glass tanks, but plastic scrapers should be used for acrylic fish tanks.

    Simply wipe down the surface of your tank with the scraper to remove it. You may need to repeat this a few times depending on the severity of the algae.

    Add Algae-Eating Species

    If your tank isn’t overstocked and large enough for more animals, adding algae-eating animals to your setup can help you manage the buildup of algae. This is a more pricey option, but it can be a good way to control algae in the long term.

    However, you’ll need to know what type of algae you’re dealing with as certain species might not eat it! For instance, otocinclus catfish prefer brown diatoms and soft green algae. Other fish like Siamese algae eaters will consume black beard algae and most other varieties.

    For a small freshwater aquarium, algae-eating species like amano shrimp, cherry shrimp, nerite snails, ramshorn snails, rosy barbs, and otocinclus catfish are great choices. For larger tanks, you can add bristlenose plecos, twig catfish, or Siamese algae eaters.

    These fish/invertebrates will also help keep your plants, substrate (gravel, sand, etc), and decorations free from algae.

    How To Prevent Algae Buildup On Glass

    Although a little algae here and there is perfectly normal, too much of it can be a sign of an underlying problem with your aquarium. That’s why it’s important to prevent it from occurring in the first place.

    Perform Frequent Water Changes

    One of the most effective ways of preventing algae is to perform frequent water changes. This will decrease the amount of nutrients that algae needs to thrive. It will also help you keep ammonia and nitrite levels at zero, and nitrates at a healthy level.

    Reduce Lighting

    Keeping your aquarium lights on for long periods or exposing your tank to too much sunlight can contribute to algae overgrowth. You should only leave your lights on for between 8 to 10 hours daily, and make sure your tank is positioned away from a window.

    Don’t Overfeed Fish

    Overfeeding your tank inhabitants can lead to excess nutrients and high phosphate levels in your tank. This will lead to algae overgrowth, so make sure you only feed your tank inhabitants as much as they can eat within a couple of minutes. Remove any leftover food with a net.

    Add Algae-Eating Fish

    Algae-eating animals like otocinclus catfish, nerite snails, Siamese algae eaters, and shrimp can help you control algae before it gets out of hand.

    Use Live Plants

    Introducing live plants to your tank will help you manage algae. They will utilize most of the nutrients in the water that the algae needs to grow.

    Test Your Water Source

    Depending on where you live, your tap water may be high in phosphates and nitrates. Both of these can contribute to the development of algae, so it’s a good idea to test your water. You may need to select a different water source for your tank or use aquarium phosphate removal products.

    How Often Should You Clean Fish Tank Glass? 

    You should clean your aquarium glass each time you perform a water change. Most fishkeepers do partial water changes once a week, so you don’t need to remove all the water.

    However, the size and stocking level of your tank will need to be taken into consideration. Smaller, overstocked aquariums will need much more frequent water changes than bigger, understocked ones.

    Is It Safe To Use Vinegar To Clean Aquarium Glass?

    Is It Safe To Use Vinegar To Clean Aquarium Glass?

    It is safe to use vinegar for cleaning aquariums, but you should only use the distilled white kind. Some other types can contain yeasts, sulfites, and additional flavors that can be harmful to aquatic life.

    White vinegar is also a great way to sterilize plants, filters, and aquarium decorations. It can also temporarily lower the pH in aquariums.

    You should still be careful when using vinegar around your aquarium. Dilute it with water first and try not to spill any in your tank water. Although a few drops won’t harm your tank inhabitants, it will lower the pH and make it more acidic in larger volumes.

    This can be dangerous for fish that need alkaline water. In addition, it can also be problematic for snails as it can dissolve their shells.

    Is It Safe To Clean A Fish Tank With Dish Soap?

    It is NEVER safe to clean a tank with dish soap! You should also avoid using sponges, buckets, cloth, etc., that have been contaminated with dish soap or other cleaning products.

    The chemicals found in dish soap will damage your fish’s gills, causing them to suffocate. 

    There will always be a small amount of residue left over from using dish soap, no matter how many times you rinse your tank. This is the same for sponges, cloths, and other equipment.

    Even a trace amount of dish soap can be lethal to aquatic animals. A much safer way to disinfect your tank, plants, and aquarium equipment is white vinegar or hydrogen peroxide/bleach mixed with water. Make sure you rinse your tank extremely well with water after using these.


    Cleaning your tank glass regularly is important for preventing the buildup of algae, film, grime, and limescale. Besides, it will make your tank look much tidier and make it easier to watch your tank inhabitants.

    Distilled white vinegar is the best way to clean a tank, especially to remove dirt and limescale.

    Only use brand-new sponges, cloths, buckets, etc., when cleaning your aquarium.

    Remember, never use dish soap and other household cleaning products as they can be harmful to aquatic life. Even a small amount can be lethal!

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