Last update: November 4, 2022

How A Padded Aquarium Mat Could Save Your Tank!

Think of an aquarium mat as a mattress for your fish tank.

It gives your aquarium a comfortable spot to rest, away from harm.

While it might not look like much, this extra piece of padding is an essential piece of equipment for many fish keepers.

And today, I’ll explain why.

Do you need a mat underneath your aquarium?

If your tank is braced, then no, you can skip the mat completely…

But, if you have a rimless aquarium, a mat is a must!

Braced aquarium and rimless aquarium needing a mat diagram

Many fish keepers skip the mat entirely, mostly because they don’t know better.

In fact, I have seen beginners throw away the mat that came with their new tank because they thought it was part of the packaging!

But I am going to get you started the right way! So, before you begin to fill your new aquarium with water and decorations, place a mat underneath.

Trust me, it’s much easier to place a mat down now rather than when your aquarium is fully set up. A filled aquarium is heavy! Unless you have a small tank or are Hercules, it’s going to be impossible to lift the tank to place a mat underneath.

Why do you need a mat under your aquarium?

Black aquarium mat underneath rimless fish tank

Like I said above, a fully setup aquarium is heavy.

On a rimless tank, most of this weight is placed on the bottom panel of glass. Not a problem – the bottom panel is up to the task of holding all that weight…

As long as the surface the tank sits on is level.

Here’s where it gets tricky – most surfaces aren’t perfectly level.

Heck, I have seen brand new aquarium stands with uneven surfaces – screw heads and knots are just some of the surface imperfections that your tank can rest on.

Not something you want pressing against the bottom of your tank, right?

The weight of your tank will be focused on any high points on the surface, placing the bottom panel of glass under focused stress.

You won’t even notice your aquarium straining against the uneven surface.

Over time, as pressure is continually applied to these points, your glass will finally give way….


Your worst nightmare – a cracked tank.

But it doesn’t have to be like this…

The spongy material of your mat absorbs those high points so that they do not apply pressure to the bottom of your aquarium.

This is why they are often referred to as leveling mats – it helps smooth out any bumps that hide below your aquarium.

It is completely possible that your tank may be just fine, even under all that pressure. But it’s an expensive risk.

And, considering just how cheap an aquarium mat is, there is little excuse not to use a mat at the base. For peace of mind, it’s worth it.

Personally, I use some kind of mat every time I set up a new aquarium.

Now, I must stress that a foam mat is only useful for raised surfaces – bumps, not gaps.

If your aquarium stand has gaps, then a foam mat is going to compress into those gaps. And, you know what that means? That’s right, uneven pressure on the base of your tank.

If gaps are the reason your aquarium isn’t level, then a mat isn’t going to help at all – you need to find a way to flatten out the surface.

Which is the best mat to use under your aquarium?

It’s funny, in Europe, you can commonly find foam aquarium mats on the shelves of local fish stores. But in America, it’s a different story. There are only a couple of brands, such as Mr. Aqua. While these are great mats, they are typically aimed at smaller aquariums.

I personally go the DIY route. When it comes to mats under my aquarium, I use something like these…

Foam camping mat used underneath aquarium

Camping mats are designed to keep you comfortable on uneven surfaces when camping. Those rocks and pebbles on the ground? Camping mats absorb them so that they don’t apply pressure to your body while you sleep.

And, they work just as well for your aquarium!

Oh, and they come in nearly any color you can think of, if that’s your thing.

While camping mats are my go-to my choice, any padded material with a bit of give can be used…

I know many hobbyists who use yoga mats as padding. If you have a short wife, maybe she won’t notice if you slice a piece off! Otherwise, cheap yoga mats can be found at any retailer.

Others use a cork mat, a popular drawer liner that can easily double as an aquarium mat.

Sometimes I even hear Styrofoam recommended for use under aquariums, but I avoid this since it crushes easily.

Whatever material you use as a mat under your aquarium, make sure that it has some give – this is what makes the mat absorb any irregularities on the surface.

Just remember that larger, heavier tanks need a denser foam since they will compress the mat more than a smaller tank.

Once you choose your mat, simply cut it to size. This way, it will be mostly hidden from view.

Foam mat cut so that it fits perfectly underneath rimless glass aquarium


I have seen some hobbyists skip the foam mat because they don’t like how it looks under their aquarium.

Trust me, if you cut away any excess foam, it is hardly noticeable. I have never once had a guest comment on the foam underneath my tanks. They are too fixated on what is going on inside the tanks to notice.

Do you use a mat as a base for your aquarium? Tell me what kind and why in the comments below!

Ian Sterling

Ian Sterling, founder of, began his aquarium journey over 30 years ago, driven by a deep fascination for fish and their diverse personalities. His website,, is dedicated to making fishkeeping accessible and enjoyable, offering beginner-friendly guidance, expert insights, and a community for aquarists to connect and share experiences.

Comments (38)

Hello there . I just got a 500 gallo acrylic tank for my house .i built a stand myself and I wanted to find out if it is necessary to put foam underneath it. The bottom is 1.5 inch acrylic and the sides also . It has a fully top brace with three openings . While placing the tank on the stand I realized that the left front side of tank is not touching the base perfectly. It’s enough for a credit card to fit thru but not a quarter and go back like 2 or 3 inches till it can’t go anymore. Should I be worried about it . I checked the level of my tank and it’s still in between the two black lines but the bubble is a little closer to the left black line. If you can give me a few pointers I would greatly appreciate it. Thank you

Hi Adrian,

I have less experience with acrylic aquariums and could not give you definitive answer to this question. If it was glass, I would be very concerned about such a gap, particularly on a large tank.

Hi Wilson,

Are you talking about the plastic bottom braces? That’s what will be supporting the weight of your tank. If the surface is slightly uneven, say very slightly bumpy, it probably won’t be an issue. If your tank is actually slanting in one direction then yeah, you will need to level that out somehow.

Hi there! Great article.
I’m currently setting up an 65 gallons aquarium (120x40cm). Initially I placed Styrofoam under the aquarium but I realized that the Styrofoam is compressed on one edge so that a lot of the front side of the aquarium is no touching the styrofoam. This is the same like Adrian’s problem in the comment above. I will fallow your advice and use a camping mat.

But I want to ask you: what thickness should I choose for the mat? My options are 6 mm or 12 mm. Should I choose the thicker one or is it ok the 6 mm thick mat?

Hi Marius,

It looks like the selections have changed since I purchased mine many years ago. I’m pretty sure mine was only 3mm. That said, mine was just to protect the tank from a very shallow knot in the wood of my stand. If your tank is substantially out, it would be better to level the stand rather than pad it out with foam. Otherwise, you would choose the size mat that will fill in the gap. The mat will compress on the side where the gap is to compensate. If your stand is out by more that 6mm then I’d certainly suggest leveling the stand rather than choosing a mat to solve the problem.

Just found you on the internet when looking what mat to use
I was going to use those interlocking floor mats
But when we put the tank on top there is a 1 or 2 mm gap in places along the front
My question is on a 10mm glass 6x2x2 timeless tank would this be ok to fill
Or should we take it back down and put yet another ply on top with no nails inbetween to level
And lastly will these mats do or should we change them out for something else

Hi Gisela,

I’d be hesitant to suggest a mat that doesn’t cover the whole bottom of your tank. If I am thinking of the same interlocking mat, it will be quite thick. If you don’t mind looking at it under you tank then it will do, I’m fussy and prefer something thinner.I’d level the surface then use a really thin mat, like those “self leveling ones” they sell at your local fish store. Speaking of which, if you have a small independent fish store, they will be able to give you some great advice on what to do too, even if they don’t have the right product in stock.

Hi Ian,
Came across you by accident and glad I did. I have 11 tanks and always used styrofoam underneath. Due to ill health all tanks but one were shut down and now I’m going to set up another 2 tanks again to start off. I tried buying more styrofoam but no aquarium places near me sell it. After reading your article i can finally start getting tanks ready using camping mats which are easy to buy. Thank you for such an informative article. You have saved me so much time and effort.

Hi Sharon,

I’m sorry to hear about your health problems. That’s awesome that you are well enough to get back in the hobby! Mats really are the way to go.

I have an Aqueon 15 gal column aquarium which has a 3″ plastic base. My stand is wrought iron with a wooden top. I noticed there’s a wobble so I put a small piece of cardboard on the back corner. That seemed to work. However, after having the aquarium set up for five months, I noticed a small leak corner wise from the corner in which I put the cardboard shim. (shim under back left corner and leak is on the front right corner about 5″ from the top). I’m in the process of resealing the side that is leaking. Do you recommend a mat? If not, what else can I do to level the aquarium? Do you think it’s due to the wood on the stand not being level? Any advice is appreciated!

Hi Teresa,

It’s hard to say, it could possibly be the stand But I’m leaning towards it being a faulty – the plastic bottom brace of your tank should support it. Also, if the leak is from a crack, then I’d suggest replacing the entire tank.

I am about to set up a reef tank using an Aquarium Masters EDGE series rimless tank from my LFS. The bottom has a plastic brace around the four sides.

Tank is 18″ x 36″ x 20″ ht

The stand is one that my LFS is selling me to fit the tank.

Will it do any harm to use the Innovative Marine DIY mat?
Thank you

Hi Tony,

I don’t see how this will harm your tank at all. Although if your tank is bottom braced and it’s a purpose made aquarium stand, it should be perfectly level anyway.

Sir, Is it ok for my aquarium having a dimension of 62″ x 18″ x 32″ (lxwxh) to have only 1/4 ” thick rubber matting? Is it ok to contain uneven surfaces on the stand? By the before the rubber matting I have place an inch thick plywood on the stand before the rubber matting.

Hi Paulo,

That would be fine, it’s to smooth out tiny imperfections rather than drastic dents A stand should be perfectly level and flat, not an uneven surface.

hi you must be the only one that has brains all other articles of the others i read and seen don’t
mentation foam or matting of any type and they call themselves pro not but ill give you 10 out of10
very good write as been in the trade 40+yrs once again great

Hi Ralph,

It’s always nice to see a fellow fishkeeper who has been in the game for years! I’m glad the article helped you out!

Hello sir,
I hv 55 litre rs 480a it necessary to keep styrofoam sheet in bottom or can i keep as it is on stand.i use wooden stand

Hi Lahiru,

If your stand is level, there should be few issues. Having the styrofoam sheet under your tank won’t hurt, of course.

I was wondering about padding *in* an aquarium! I’m setting up a new 10 gallon (rimmed) tank, and want to put a couple of 2.5 pound rocks in it – should I be putting something under them in the aquarium? If so, what?

Hi Julie,

The substrate, such as sand, is the padding. This helps spread the weight evenly across the surface of the glass. The substrate should be a good depth (generally 2-3 inches or so I have never heard of anyone place padding at the bottom of their tank on the inside. A 10 gallon reef tank will often have have 10-20 pounds of live rock inside them.

Hi there,

I have seen people on YouTube put pieces of thick styrofoam on the bottom of their tank under any larger rocks. It seemed like a good idea, but it might not be for some unfrozen reason. The channel, green machine on YouTube has great tutorials.

Hi Ray,

Good question! I don’t like Styrofoam because it’s more noticeable and will crumble as it ages – I’m not a fan of those tiny white flakes that get everywhere. This is my personal opinion, I know quite a few fish keepers who use it instead of a mat. I’m just a bit fussy here.

Dear Mr Sterling,
Thank you for a very interesting article. I was just about to order a mat! My second hand Aquastabil aquarium bought in June cracked with a wide arch shape Friday night. 200 litres on the living room floor. It was braced, on a stand. I can see it was “sick glass” = white faint spotted areas on the side that cracked and also on the other long side. I have ordered a new aquarium, which is also braced, but will stand on a table from the aquarium manufacturer (both 100*45cm, 220 litre tank).
You seem certain that we won’t need a mat under a braced tank (and I would agree) – but wouldn’t it help at all to cut a mat that fits perfectly to the framed bottom, lying snugly between the bottom glass an table (inside the bracing)?
My husband and I are worried about another cracked tank! Thankful for any thoughts on this matter.

Hi Iril,

I’m so sorry to hear about your misfortune. That must have been an nightmare to return too 🙁

I see no harm at all in doing that. I have no experience with it, as the brace should be appropriate to support a properly constructed tank. I know if I ever experienced a breakage, I would very likely go all out on stopping it from happening again – so I understand your caution!

I am setting up a 45 gallon rimless JBJ aquarium on a stand manufactured by JBJ. It has a high gloss finish, don’t love how it looks, but that’s besides the point. My question is, with that smooth of a surface, and the fact that I leveled the stand in each direction, is it still advisable to get a mat underneath my tank? I haven’t put water in it yet, it just just sitting empty on the stand waiting for me to begin work on it. Thanks for the advice!

Hi Chris,

This would be a question to ask JBL themselves. Given that they have manufactured the stand specifically for this tank, it’s likely that the mat could be skipped.

Hi Ian,

Thanks for the article, just what I was looking for.

I have recently purchased a Juwel Vision 180. See here –

I don’t have anywhere to place the cabinet, so I’ve popped it on a shelf in an alcove.

Juwel have suggested placing some foam down on the existing shelf directly and then placing another piece of custom cut wood on top of that. Reason being that this is a ‘floating’ tank and it needs to be on a completely flat surface.

What are your thoughts on the above and what foam would you suggest?

Hi Ed,

I’m unfamiliar with using foam underneath the actual cut wood. I’d suggest contacting Juwel direct on this one.

Hi! I heard on a YouTube video that rimmed tanks should definitely NOT use a mat. The reasoning was because the rim is designed to support the weight, and if you use a mat, it puts stress on the bottom panel of glass. That being said, I have a thick kitchen floor mat under my 20 gallon, and I’m worried now!! Will it break? Should I take it out next time I do 50% water change??

Hi Allison,

I assume you are are talking about a braced aquarium, where the bottom brace supports the tank? If the brace is taking the weight and not the glass underneath despite being on the mat, then it shouldn’t be an issue.

I just picked up a 7g cube rimless tank. It came with a leveling mat already attached to the bottom of the tank. My issue is that the mat is not covering the entire bottom. It looks like it is covering the entire bottom glass piece but doesn’t cover the side glass pieces. Should I be ok or do i need to pull that mat off and attach a new one?

Side Note. It’s odd. I bought two Seapora rimless tanks from the same shop the same day with lids. The 7g has the mat attached and it came with a acrylic lid. The 4g came with an appropriately sized mat but loose and the lid was glass with a handle i had to stick on but i couldn’t because it didn’t fit the tank. Ended up getting a poly-carbonate one made instead.

Hi Greg,

I am having trouble picturing your tank. Are the sides braces? If it’s braced, you may not need a mat at all.

I have a 100g tank with about 100 lbs. or more of substrate and rocks in it. The stand is wood. The thing that bothers me is that the aquarium just sits atop this wooden stand. I often worry that having this 1000+ lb. aquarium atop a wooden stand could result in a dangerous disaster. I’m considering purchasing 3 – 100g water heater tank stands and a Duralex recycled tire link entrance mat (on Amazon), to place my aquarium on. The water heater stands are just 18″ high, which is ideal for me because I am short. Plus, I would like to try some aquaponics growing with this aquarium, thus, the shortened height will accommodate. One concern is the tire link mat. The links are woven with galvanized steel wire. I’m wondering if the weight of the aquarium will smash the tire surface down so much, that the wires might dig into the bottom of the aquarium. Please give me your input. Thank you.

Hi Carolyn,

Unfortunately, I cannot help you on this one. I don’t have any experience with the duralex recycled tire link mat.

Hi Ian,

Thanks for your response.

I decided to go with an anti- fatigue rubber mat with holes, used in commercial kitchens. Do you think it will suffice?

Hi Carolyn,

I would recommend buying rubber that is uniform in it’s composition. A mat with holes may mean there are areas of your tank that are unsupported.

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