How To Clean Aquarium Glass & Acrylic (Outside & Inside)

Image by agkaimal from Pixabay
Image by agkaimal from Pixabay

How To Clean Aquarium Glass & Acrylic (Outside & Inside)


Cleaning your aquarium can be a lot of work depending on how you go about it so the last thing you want to do is a half job. Before you start applying products and sponges to your aquarium, you should consider what you are trying to do with your cleaning and what type of aquarium you have. If you only need to clean the glass, there are a couple of methods that will help to clean the glass safely without having to disrupt your fish’s lives by temporarily relocating them to another aquarium.

If you have an acrylic aquarium, make sure to see the acrylic tank section as your glass is much more sensitive than normal aquarium glass. You want to make sure you avoid more abrasive scrubbing products.

Tools For Cleaning Glass & Acrylic

Magnetic Glass

Algae Glass

Algae Acrylic

Fish-Safe Cleaning

Water stains are a natural part of owning an aquarium and there will come a time when you have to deal with them. Hard water stains are caused as the tap water from your fish tank evaporates and leaves a mineral buildup on the sides and lid of your fish tank. All tap water will have this buildup and the minerals are actually crucial for fish health, but the stains can leave an eyesore.

You may be tempted to grab your favorite cleaner from the cabinet to clean your fish tank but you should avoid doing so at any cost. Regular glass cleaner is extremely dangerous for fish. Even if you try to be careful and apply very little to a cloth or directly on the affected area, you are risking introducing a toxin into your fish’s habitat. It only takes a little bit of a cleaner to kill your fish so to avoid heartache, you should look for fish safe alternatives.

If you are unable to find the fish safe cleaning products, there are a few common household items that may help you just as well like vinegar. You may also want to consider not emptying your reef tank to clean it every single time. Aquariums build up a lot of beneficial bacteria that help to keep a reef healthy and safe for its inhabitants but if you are emptying it to clean it all the time, that beneficial bacteria will never build-up for the ecosystem of your fish tank. However, that means when you clean your tank, you want to ensure that the methods you are employing are not putting your fish in danger or risking any damage to the aquarium itself.

Fish-safe cleaning spray or lime removal

The biggest benefit to cleaning your fish tank with a fish safe spray is that it will be much faster than using a home remedy cleaning method. You can clean the outside glass with the fish-safe lime remover but once you are done you should follow up with a quick rinse using a damp microfiber cloth. You will not only prevent any scratches this way, but you will ensure that the product is completely whisked away, and this will help to prevent smears. The only issue with these products is that they can be a little more pricey than say vinegar but if you find they work more efficiently then more power to you. All that matters is that the job is getting done safely and effectively.

How to clean the glass with vinegar

Vinegar is an easy and accessible option for cleaning aquarium glass. First, you will need a few things before you begin going to town on your aquarium glass. You will need white vinegar, sponges, algae cleaner, table salt, and possibly a razor blade. These steps will be based on a glass aquarium tank. The method with how you clean with vinegar is pretty universal for all deep cleaning methods just with different products. The most important thing to remember is that if you are using a commercial cleaner that it is marked as fish safe. Even better, look at user reviews for that product and see that no one is complaining that their fish got sick from the product.

Empty your tank

If you are trying to have a deep clean of your fish tank then you are going to need to empty your aquarium and find a nice temporary home for your fish as well as live plants, decor, and water. However, this part of the process might not be required. If you do not think that your fish tank needs toa serious cleaning, consider looking at the other methods listed in this article to clean your tank with a lot less hassle. This method is also very good to make sure that the old glass fish tank you found at your grandparent’s house is safely cleaned and can be used again.

Sponge pre-scrub

You can begin to scrub at the walls of your aquarium very carefully with a wet sponge. This will help to loosen up any of the algae and mineral buildup and make the rest of the task must easier in the long run. Use the salt on the sponge after the first wipe and carefully scrub the tank clean again. Let sit for about 3-5 minutes.

Time to rinse

Rinse off all the grime that you were just scrubbing around in the aquarium. The process is to get the excess salt and algae out of your aquarium and so you can get a better sense of how your tank is looking so far in the process.


Use the algae cleaner to help remove another layer of the caked-on algae and mineral deposits. If there is too much algae or minerals present, you will need to use a razor blade to scrape it off. It is a razor blade so be careful and if you have gardening gloves or other hearty gloves, consider using them to reduce the risk of injury.

Vinegar time

In a small container, combine one part vinegar and one part water and use a clean sponge to apply the solution to the glass of the aquarium. Scrub the whole tank until it looks pristine where all the algae and stained minerals are lifted off. Once you are done, you can rinse the aquarium once again.

How to clean algae from fish tank glass without emptying it

If you do not need to do a deep clean of your aquarium, then this method is much easier and will save you a lot of time. All you need to do is take your magnetic algae cleaner and apply a little bit of vinegar to the scrubber side then begin scrubbing. As always, you should be careful while scrubbing and watch that you are careful near the bottom of the tank because. When sand gets trapped in the magnetic algae scrubber, you run the risk of scratching the glass of your tank. You should invest in an algae scraper for the inside of your tank to help remove algae but be careful not to knock into anything inside your tank! As long as you are careful, you will have a clean aquarium in no time.

Cleaning outside aquarium glass

Easy, you can use aquarium safe cleaners applied to sponges or microfibers cloths or you can use vinegar in the same way. Scrub over the entire tank and when you’re finished, go over the tank a few times with a wet cloth. Depending on how your tank is looking you might want to polish it up from any scratches it might have as well.

How to safely clean acrylic aquarium

There is a difference in care between glass and acrylic aquariums so knowing the differences will help ensure that you are taking the proper care while cleaning aquarium glass. Acrylic glass has a lot of benefits like being much more difficult to break than normal glass or being much lighter. No longer must we struggle as much to get the tank up the stairs to our offices, but we do have to be much more careful not to scratch the surface of the acrylic glass. The acrylic is strong but if we want to keep it beautiful then we need to know how to properly care for it. It will take a bit of work, but you will be thankful that you took the necessary precautions.

There are a few things to consider before you begin scrubbing the acrylic. Have you removed the sand or other loose debris from your tank? That debris can get stuck in the pad of your scrubber and cause havoc to the acrylic as your work. Which of course means, you need to safely relocate your fish and drain your tank.

Just as there are fish safe sprays, there are acrylic safe products to help your polish your tank. Use a microfiber cloth for careful scrubbing of the walls of your tank. Depending on how much algae has built up, you may need to try to use a plastic algae scraper. There can be bad angles at which your approach the scrubbing that could cause tiny scrapes. You want to make sure the algae scraper is safely flat against the acrylic glass to ensure that the algae scraper doesn’t scratch the glass.

Preventing scratches to normal aquarium glass is relatively simple but depending on the kind of aquarium you have the precautions you take might change. As I have mentioned earlier in this article, if you have a sand bottom to your tank, you need to be extremely careful if you choose to use a magnetic algae scraper. The only issue with this is I you don’t empty the tank, you will need to get your arm a little wet. The algae scraper is bulkier so you need to watch that you don’t hit any of your corals or live rock while you clean. If you have a sandy bottom, it is entirely possible how often you deep clean your tank will increase as there will be places that you aren’t able to reach like you might have been able to with a magnetic scraper.

How often to clean aquarium glass

You should be cleaning your glass as often as you clean your tank so every 2 weeks or so. The frequency can change depending on the setup of your aquarium so you should have a better idea of how often you should clean your aquarium. Depending on the type of cleaning you are doing to your tank should determine how you will approach cleaning your tank’s glass. If you are seeing that there is a larger buildup of algae than normal between intervals then there might be something wrong with your tank’s water quality or filtration. However, you will not know what normal is until you are familiar with your specific saltwater reef tank so give it time and check your measurements whenever you clean to be sure.

Final thoughts

Now, you should have a good idea of how to approach cleaning your aquarium. It doesn’t have to be all that hard but you to make sure you are being careful when deciding what method and approach you to decide on. Draining all the water from your aquarium might seem like a great idea but it can disrupt the life that is building itself within your established aquarium. Deep cleans should be a last resort as often as possible to prevent any unnecessary disruptions to your aquarium. Invest in some microfiber cloths because they can be the biggest asset in working with glass and preventing scratches but if you do begin to develop scratches you can always invest in fish-safe polishes. For more tips and guides to care for your aquarium, please be sure to follow us at Reef Tank Resource.

Did you find this article helpful? Help Us & Share it.
Recent Posts