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How To Get Suction Cups To Stick In Your Aquarium: 4 Tips & Tricks

Lindsey Stanton Profile Picture

By Lindsey Stanton

co2 aquarium

Depending on who you ask, suction cups really are great inventions. They allow you to stick stuff to smooth surfaces without much effort at all. This is why some fish tank filters, bubblers, lights, thermometers, and other aquarium accessories use suction cups as mounting methods.

They are cheap and easy to use. However, they don’t always get the suction you need to support whatever aquarium equipment needs supporting. Today we want to specifically talk about how to get suction cups to stick in aquariums—it’s actually a common issue and frustration.

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The 4 Tips & Tricks on How to Get Suction Cups to Stick in Your Aquarium

So, your aquarium suction cups are not sticking, and it is a problem because your filtration unit, thermometer, or whatever else you are looking to stick to your aquarium wall keeps falling to the bottom of the tank, and maybe even getting damaged too.

How do you get aquarium suction cups to stick so that whatever you have attached to them does not come crashing down?

1. Apply Suction Cups to Dry & Clean Glass

One of the biggest mistakes that people tend to make when trying to stick suction cups to their aquarium is to apply them when there is already water in the tank. If there is already water in the aquarium, it will stop the suction cups from being able to suction on well. All of that water behind the cup gets in the way and prevents solid suction from occurring.

This is also the case if there is algae, dirt, or other debris present on the glass. Anything that gets in the way of direct, total, and full contact between the suction cup and the wall of your aquarium is going to cause problems.

Therefore, to get the suction cups to stick well, you need to apply them to very clean and dry glass. It’s really the only way to get proper suction with suction cups in your aquarium.

Acrylic fish tank
Image Credit: BLUR LIFE 1975, Shutterstock

2. Make Sure Suction Cups Are Clean

Just like if the aquarium is dirty or wet, if the suction cups have debris on them, they also won’t stick right. Now, a little trick here is to make sure that the suction cups are clean. However, the suction cups do not need to be 100% dry. If they are slightly moist, the moisture will help form a better seal and help them stick better. They should not be soaking wet, just a little moist, to get that ideal suction.

If your suction cups are very dirty, some good old dish soap or vinegar should do the trick, but be sure to wash and rinse them thoroughly with warm water to prevent any unwanted elements from getting into the water.

3. Get New Suction Cups

Another problem with your suction cups might just be that they are old and worn down. Your suction cups need to be in prime condition if you have any hopes of them sticking properly. This is especially true when it comes to the outer edges of the circle. For there to be tight suction or really any suction at all, the suction cups need to be totally airtight.

This means that they cannot have frayed edges or missing pieces on the edges. The edges also need to be flat and even, plus there cannot be any holes in the suction cups either. If your suction cups are old and worn out, besides buying new ones, there is absolutely nothing you will be able to do to get these to stick.

Suction cups are not high tech and they usually are not built to last, so chances are that you will end up replacing aquarium suction cups fairly often.

4. Use Magnetic Suction Cups

Okay, so dealing with suction cups is not all that enjoyable. However, there are magnetic suction cups out there, and they work pretty darn well. In all reality, magnetic suction cups are not suction cups at all. They use magnets that hold to each other from one side of the tank to another.

Even though they are not really suction cups and use magnets instead, they look like them and work like a charm, and you never have to worry about using normal suction cups again.


starfish divider ahApplying a Suction Cup the Right Way

One tip here is to hold your hand on the opposite side of the glass where you plan on putting the suction cup, and lightly press from one side of the glass as you push the suction cup on from the other side.

Make sure to hold the suction cup in the middle, right over the center part, and press firmly against the glass until all of the air has escaped from between the aquarium wall and the suction cup.

It’s really the only and the best way to help make sure that your suction cups stick well to the aquarium walls.

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So, if you are having issues with getting your aquarium suction cups to stick properly, you might just have to clean your aquarium walls and make sure that they are dry before applying them. Cleaning the suction cups themselves and giving them a little lick of the tongue before applying them can help too. However, you might just have old and worn-down suction cups, in which case they will need replacing.

You can also try magnetic suction cups, and although they really do not have much to do with suction cups as we know them, they are easy to use and they work well.

Featured Image Credit: BLUR LIFE 1975, Shutterstock

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