How to Level an Aquarium: Everything you Need to Know

Written by Randy Martin
Aquarium with level in foreground

Making sure your aquarium is leveled is important. I wanted to share some helpful methods, tips and tricks I have picked up along the way as I have personally wrestled with several tanks trying to level them.

How to level an aquarium? To level an aquarium it is best to level the furniture or stand the aquarium is sitting on, not the aquarium itself. Use shims under the stand when needed. If the stand is level but the tank is not sitting on it properly, then an aquarium leveling mat or sheet of styrofoam may be used to smooth out the irregularities.

We will get into everything you need to know and hopefully address all questions you may have when trying to get your tank to sit right.

Tools you may need:

  • Level
  • Shims
  • Rubber mallet
  • Crowbar
  • Piece of styrofoam or aquarium leveling mat

The process is really simple so it doesn’t take much. A rubber mallet to gently beat in the shims if you are on carpet. If you are on hard floors you may need a crowbar to lift the stand.

And in some cases but not all, you can use a leveling pad or mat underneath your aquarium.

The basics of leveling an aquarium

First let me go over a few of the basic ideas up front.

Why it’s important to level your fish tank

The main reason this is important is due to stress. When you have a tank that isn’t sitting level, you will have one side or corner that is holding more water and weight.

For aquariums that have glass pieces that are glued together with silicone, this extra weight can actually warp the tank, break seams and cause a leak in your aquarium.

This has happened to many people in the past.

Imagine the emergency situation—all the water pouring out onto your home floors and the lives of your pet fish in jeopardy.

This is one of the reasons that the main aquarium that I review and recommend here in my post, is one full piece of acrylic for amazing strength.

So making sure it is all level is really important to avoid that stress, especially for bigger fish tanks.

The bigger the size, the more weight it can hold, therefore the more stress it can produce.

And it’s still important for acrylic tanks too that aren’t glued together.

A note about your floors

Floors are rarely level. Basing everything on your floors is not the way to go about it. Make sure you are leveling the piece of furniture or stand that your aquarium sits on.

It is important that your stand is sitting even on the ground. So the furniture is distributing the weight evenly as well.

I mean just as much as an aquarium could break and buckle under the water weight, your furniture could too.

There will be differences if you are on carpet or a hard wood / concrete floor. If you are on carpet it will be a lot easier to shim. On a hard surface you might have to bust out a crowbar to lift and shim it if there is already a lot of weight you are working with.

Setting up your fish tank from the start

If you are starting an aquarium brand new then this is the best time to get it all leveled.

Now would be the time to determine where the tank will be located. Get your stand or piece of furniture where your tank will rest on. Set it in place and check the top surface and sides with a level.

Since there won’t be much weight right now it should be easy to shim the piece of furniture to get it as close to level as possible. Also shim any corners or areas that the stand isn’t touching the floor to make it more sturdy.

It’s a good idea to do a shake test. Lightly shake and rock the stand around to check how solid it feels. You can put your aquarium on top and move it around a bit to see where there is play in the movement. Shim it as you need to, in order to solidify it further.

Doing all this while the aquarium is empty is very useful. But you may find a lot of times that as water is added to the tank that the extra weight can actually help self level the stand and aquarium.

The water can sometimes even out the weight and make your stand sit more solidly. It sorts of puts it in its place.

How to level an aquarium

As I said in the beginning you want to focus on leveling the furniture or the aquarium stand more so than the aquarium itself. You want the whole setup to be as solid and sturdy as possible.

You should have a level however big or small, as long as it’s accurate, to check the level of the surfaces.

Although if your tank is already setup and it’s filled with water, you can typically just look at the water surface and eyeball if it’s sitting level or not.

It’s best to be extremely accurate with an actual level tool though, and this is even more important if you have a much larger aquarium.


The best way to level the stand is to use shims. They are widely available at any hardware or home improvement store and you can get a bundle for really cheap.

Using shims to raise your aquarium is a very simple process.

How to shim an aquarium stand—step by step:

  • Determine which side needs to be raised.
  • Insert the smaller end of the shim between the stand and the floor.
  • Then use a rubber mallet to easily beat the shim in further. The deeper it goes, the wider the shim is, and the more it will lift the stand. You may use multiple shims stacked on top of each other for a higher lift in areas where it’s needed.
  • Then when the shim is in as far as you need it to be, you can just lift up on the shim to break it into two pieces, leaving the one end under the stand, and removing the rest so it’s not sticking out. In some cases you may need to saw away any excess shim that is sticking out, just take great caution with the floor and the piece of furniture.
  • Shim each side evenly. So go down the entire side that you are raising and shim it every 6 inches or so.

This will be very easy on a carpet floor, as you don’t need to lift the stand. The shim will be easy to slip underneath it and on top of the carpet with a mallet.

If you are on a hard floor then you might need to use a small crowbar to lift the stand ever so slightly. It will probably take two people to do this. One to lift and the other to drive the shim in.

Likewise if your aquarium is already filled with water or there is a lot of weight, you may need to use a crowbar even if it’s on carpet.

In either case, place a sheet of cardboard or something underneath your crowbar to protect your floor.

These shims even though they are very simple, they work out very well. And I have never seen them give way or crush underneath the weight in very large aquariums that can hold hundreds of gallons.

Using an aquarium leveling mat or styrofoam

There are special aquarium leveling mats that are designed to be placed directly under the aquarium itself to level it out. It’s a semi thick mat that compresses under the weight and in theory will flatten the surface evenly.

These are sometimes even shipped out with aquarium starter packages. Other people just use a fairly thin sheet of styroam to do the job also.

Now these are useful, but they should not be your main tool or resource to leveling your fish tank.

Important: Using an aquarium leveling mat is not a substitute for manually leveling your stand. They can be used but only after you are sure the stand is level.

If you got your stand totally level and sturdy, but there are still some bumps or gaps on the surface where your tank will sit. Or if the bottom of your tank’s frame is warped a little, then you may use the mat or styrofoam under the aquarium so that it will rest on a flatter and even surface.

You can easily cut these to the shape of your tank so it’s not sticking out or showing in any places.

You would probably want to use a some kind of buffer mat like this if you have an aquarium where the bottom sits flat on the surface. Like the acrylic aquarium I recommend above, there is no frame so the acrylic sits flush with the surface.

Putting it on a mat makes sense to have it sit better on the top surface, also to avoid any scratching or damage to the bottom of the tank.

If your furniture has 4 legs instead of sides

Putting shims under a full sided piece of furniture is easy and makes sense, but it’s not always logical when the piece of furniture has legs.

In that case it may be better to use square wooden slats if you are on carpet. Just raise the stand and place the slats under each leg until you have got it leveled and solid feeling.

You can also find cheap wooden slats at hardware stores. There is other options you can try out. It should be easy to find no-slip slats that are designed for dining tables for example. Those usually have foam pads that the legs will sit on which will further help the leveling.

This could be a good option especially for metal pieces of furniture and also for hard floor surfaces as you don’t want them to be able to slide around.

But you can always get creative and do what you must. I have a friend that literally sanded down the legs on his wooden stand until they would sit completely level on the floor.

Related Questions

Aquarium stand on carpet? Using an aquarium stand on carpet is perfectly fine. You have to be more careful with water changes and leaks so you don’t get your carpet wet. Using shims under the aquarium stand where needed, to make sure it sits level on your carpet is an important consideration.

There is a gap between aquarium and stand, what can I do? First make sure your stand is leveled. After it is level if there is still gaps, then it is usually caused by warps in the stand or aquarium frame. You can sit the aquarium on a leveling mat or foam pad to fill in the gaps, and to distribute the weight evenly on the surface.

How level should an aquarium be? It is important to have your aquarium leveled so the weight is sitting evenly and no corner is being overly stressed, which might cause a break and leakage. The bigger your aquarium is, the more important it is to be extremely leveled.

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  1. Mike on said:

    I got a new 55 gallon aquarium the stand and Aquarium are pretty level with shims on a hardwood floor but the whole thing still rocks a little bit

    • Randy Martin on said:

      Keep working on it until it’s stable before you fill it up with water. You want to make sure it’s solid and all of the movement is taken out of it. If you shimmed it up and there is still movement it might be the stand itself and may need to be reinforced. Good luck with your new aquarium!