The Best Way to Re-Store Your Aquarium Suction Cups

Last Updated on March 27, 2022 by cmoarz

Aquarium Suction Cups are a great way to hold things in place, but they often fail over time. This is usually due to the accumulation of dirt and dust, which can prevent the cup from creating a strong seal. Aquarium lights or sunlight degrading the suction cup as well as just general long-term use underwater. Fortunately, there are a few ways to revive old suction cups and get them working again.

What are suction cups and how do they work

To get a handle on how to revive old suction cups you need to understand how they work. If you already understand how they work, go ahead and skip to the next header in this article!

Suction cups are a type of adhesive device that uses surface tension to create a vacuum.

This vacuum is created by the air inside the cup, which is prevented from escaping by the surface of the object being held.

This creates a strong seal that can hold up to a certain amount of weight (depending on what the suction cup is rated for.

A good rule of thumb when picking out your suction cups is for every inch in diameter your suction cup is, it’s capable of holding around 6lbs (2.7kg) of weight before breaking suction.

Suction cups are often used in place of clamps or magnets, as they are reusable and do not damage the surface they are attached to, which is very convenient in an aquarium where glass is easily scratched and adhesive can be toxic.

What causes suction cup failure

Suction cups work best on smooth surfaces that are free of dust and dirt. If the surface is too dirty or rough, the seal will be weakened and the cup may fall off.

Aquarium suction cups really take the brunt of this due to being constantly submerged in water.

The build-up of calcium, algae, and other deposits on the glass can make it difficult for the suction cups to maintain a seal.

Worn-out edges and holes from degradation can also play a factor, as these provide an escape route for the vacuum.

It’s easier to replace a suction cup that has developed holes or has become too rough and brittle around the edges to hold a vacuum, but luckily, there are ways to restore older worn-out suction cups to make them last a bit longer.

How to clean and restore suction cups

There are two factors that go into whether a suction cup is going to stick strong or lose suction.

These are the surface it’s attached to, And the integrity of the suction cup itself.

We’ll go over how to clean both the suction cup and the surface it’s attached to so you can get the best possible results.

Cleaning the surface

To get a good stick you need a smooth clean surface. Glass in an aquarium is an ideal suction cup surface, However, it’s plagued by calcium deposits, algae growth, and various other debris you find floating around in an aquarium.

The first step is to clean the glass really well. You can use a glass scraper, razor blade, or another sharp object to remove any build-up on the surface.

Be careful not to scratch the glass while doing this.

Once the majority of the debris is removed, you can use aquarium algae scouring sponge to give it a good once-over clean.

Personal tip: If you have floating plants such as duckweed in your tank, They always seem to find their way between the glass wall and the suction cup, So be sure to check to see if any are there that could prevent sealing!

Cleaning and repairing the suction cup

Now that the surface is prepped, it’s time to clean the suction cup itself.

If your suction cup has just been unmaintained for a while and has accumulated dirt and dust, A good rinse with aquarium water and a sponge scrub should be enough to get it sticking again.

For older more worn-out suction cups with wrinkles up edges, You may not be able to repair them to fully functional levels.

The nature of having these products inside an aquarium makes it difficult to use methods that normally would resolve the suction cup degradation temporarily, such as petroleum jelly or oil, which are toxic to a fish tank.

For holes, You can generally patch these up with a bit of silicone or hot glue gun glue. Depending on the size of the hole, It might not be able to fully repair the suction cup, but it will allow you to still use it for a while.

How to store suction cups when not in use

Believe it or not, how you store your suction cups can determine how much degradation happens even when you aren’t using them.

For long-term storage, it’s best to store suction cups in a cool dry, and DARK place.

A lot of people will store them on or near their aquariums, But this can cause the suction cups to slowly degrade from the moisture in the air and contact with direct sunlight.

The same goes for storing them in an area of high humidity, such as a bathroom.

It’s also important to make sure that the suction cups are not stored in direct sunlight, as this can cause the plastic to become brittle and crack over time.

If you want to keep your suction cups near your aquarium for easy access, it’s best to invest in a storage container that is dark and waterproof.

Problems with suction cups and how to solve them

There are a few common problems that can occur with suction cups. These are holes, wrinkles, and degradation from sun and water exposure.

Holes can be patched up with silicone or hot glue, but this might not fix the suction cup completely. Wrinkles can sometimes be smoothed out, but this is not always effective. Degradation from sun exposure is usually irreversible.

The best way to prevent these problems is to clean and store the suction cups properly when they’re not in use.

Suction cups that seem to constantly fall down the glass but don’t lose suction can be caused by having too much weight on them or not enough surface area in contact with the glass.

To fix this, you can try moving the suction cup to a different location or adding less weight to it. If that doesn’t work, you can try using a bigger suction cup.

If you have a hang-on inside filter being held up by suction cups, consider lowering it a bit so the buoyancy also helps keep the weight up to where it’s supposed to be.

In conclusion, it’s not always possible to revive old suction cups, but when it is, usually all it takes is a good scrubbing of the surface and the cup itself. Be sure to clean and store your suction cups properly when not in use to prolong their life. Thanks for reading!


Owner of and also owner of actual Aquarium Gravel believe it or not! ;). Setting up beautiful aquarium sceneries and habitats since I was very young. Enjoy!