Inside Wall Aquarium Blog

Tips for DIY "Built in fish tanks".

Home » Articles posted by Aquaria-man

WallTanks on Facebook

WallTanks on Facebook

Have you checked out WallTanks on Facebook?  It’s a good place to look at other builds, get trim ideas and see what fish people recommend. We post regular wall aquarium pictures and articles from the internet. Follow our page to keep up to date with the latest specials from Even if you’re on the fence about wall aquariums, Facebook can be a good place to conduct research, ask questions and learn about the hobby. Even if you don’t have Facebook you can bookmark this link: check it periodically or search for “Wall tanks” on Facebook home page.

Wall trim options

First figure out which wall you want to use? Is the aquarium going to be viewable on one or both sides? Will you access the aquarium from the front or back?

With single-sided viewing and front access, typically you will have a picture frame style border with the top piece removable or hinged. With double sided viewing one or both sides will have trim with access under the top panel.

Baseboard trim, crown molding and wood boards all make good trim. Avoid MDF because it swells when wet. We sell pre made square and curved trim out of knotty pine here:


In-Wall Aquarium configurations.

There are a few different ways you can configure a built-in wall aquarium.  For clarity purposes I will refer to the 2 sides of the wall as side A and side B.  Let start with the best.  The ultimate in-wall aquarium will have side A and side B finished and trimmed out.  This tank sits flush on both sides of the wall so anyway you look at it, it’s a beautiful clean sharp feature of the house.  No wires can be seen and if you look through the tank you will see fish and another room.  For installs where the aquarium is wider than the wall you can have one or both sides overhanging.  This is not a problem as long as the tank is completely supported underneath with 1 1/2″ of plywood or solid wood screwed into the wall framing.  The tank should be boxed in with trim to finished the look.


If side B is a closet or basement or you just don’t want to see through the tank only side A needs to be finished.  If possible the tank should be accessed from side B.  It will be easier for maintenance than one that is completely sealed in.  A backdrop will block anybody from seeing through the tank.


When you look into a built in aquarium you will not be able to see any wires or wood inside the wall.  The ends inside the wall will reflect like a mirror.

Does a wall aquarium have to be in a wall?

IMG_3647No, any tank that is built-in is a wall aquarium.  I just finished my 250 gallon built-in tank.  This tank is 2’ deep so instead of dry walling it in, it makes more sense to have cabinets below and above for the filter, storage and ease of maintenance.  A second wall was opened for viewing from another room.  This adds a focal point to that room and visitors that see this end first are blown away by the depth of the tank.  This was a 8′ closest but makes a much better super tank!

How hard is it to build a fish tank into your wall?


Quick answer, it’s not hard if you’re handy. Anyone who has experience with drywall and a basic understanding of how a stud wall is built can put a tank into their wall. The only other skill that’s helpful is knowledge of electrical wiring.

First you’re going to cut a hole. You need to know if that’s a load bearing wall or not. If it is you will have to brace it in such a fashion that you transfer the load around the tank. Next you going to finish the stud work and construct a nice flat base for the tank to sit on.

A GFI electrical outlet should be placed in the top corner at this point. If you do not know how to do this you might need to call a friend who does. Then the tank goes in the space, patch up your drywall and trim it out with some wood. Not a hard job if you know what you’re doing.

More detailed instructions:


Realistic 3d rock wall background


Above is a picture of the background from my tank.  I love the realistic texture of the rocks and the fact that they stick out (some pretty far) into the tank.  There are also caves built into the background that smaller fish can swim through (covered in pic by my giant Oscar).

This background was made with 2″ sheets of white styrafoam insulation, silicone and cement.  First I carved up the styrafoam into rocky shapes and  bonded together with silicone.  I made it in sections so I could put them in the tank after.  Where there are caves I put 2 layers of styrafoam hollowing out the back layer.

Once the styrafoam was sculpted I started to paint/pour cement right on top.  I did 3 layers and I added black and white cement coloring to accent dark and light spots.  I tried to keep it wet with a spray bottle while I was making it so the cement will cure properly.

Then the panels went into the tank.  They were siliconed to the back and I rinsed 3 or 4 times over a week period until my ph levels dropped to a safe level.

It took around 2 weeks to make the background in my spare time and 1 week to rinse but looks awesome, well worth it.  There are a couple spots where the cement has eroded off, I plan on covering these with Java moss.

In-Walls VS Wall Mounts.

vs3Wall mount tanks and In-Wall aquariums are similar but very different.  Let’s examine.  Both look cool, have a nice viewing area, have light, filter and heater but that’s where the similarities end.  An In-wall aquarium gets built into your wall while a wall mount hangs more or less like a picture.  A fish tank built in can be much larger meaning much larger and more fish.  In fact since a wall mount hangs it does not have enough support to hold much water and therefore it’s extremely limited.  It may look cool but ultimately not be satisfying with your fish options.

Another major difference is the finished look or wow factor.  A built in tank with the front flush with the wall looks awesome!  Now finish both sides and peer through the aquarium between rooms.  This is the ultimate fish tank.  You can think of a wall mount as a toy compared to a flush see through in-wall tank.

Of course the wall mounts have some pros.  It’s much easier to install.  Typically you might be adding some screws or plywood to the wall and an electrical outlet but not much else.  A built in tank requires more labor, materials and know-how.  A typical built-in tank can take 2 days compared to 2 hours.  A built-in might cost more in the end but if you’re doing the work yourself it’s not much different.

Obviously I am recommending a built-in tank.  I have one, I love it!  But I am handy and have the experience to do all the work myself.  If you do not have the know-how or can’t be bothered to go through the work than an unsatisfying wall mount might be for you.


How to clean a Built in Aquarium.

For cleaning this tank you open the trim at top.

Cleaning a fish tank in your wall is basically the same as cleaning a tank outside your wall.  The only difference is that you have less elbow room.  First you will have to gain access to the top of the tank.  This is typically achieved through the top piece of trim.  The trim flips up on invisible hinges or lefts off with Velcro etc…  If the backside of the tank is not finished you can leave it open at the top and access it that way.

Once you have access maintenance proceeds like any other tank.  You will remove around 1/3 the water through a siphon tube.  While you are sucking the water out the waste in the gravel should be removed.  When the correct amount of water removed replace it with tap water and some water conditioner.

The tank does not move and the fish do not come out.

About us:

We are the only organization in the world promoting and providing aquariums made specifically to go inside walls. We manufacture wall aquariums, finishing trims and accessories. Our blog and instructions are here to educate and help you through the installation process .

This year we will be adding installation and product videos to our website. All our aquariums now come with LED lights for premium plant and coral growth. Check out all our different wall aquariums at .


Electrical around aquariums

Disclaimer: Although I have a fair amount of experience with electrical work I am not an electrician. You may need a qualified electrician to do the electrical around your aquarium. Check your local by-laws.

To prevent any shock hazard you should install a GFCI outlet. This is the same type of outlet you’ll find in your bathroom.   A typical aquarium will have a light, filter and heater. Some larger aquariums like our Jumbo Wall Aquarium has 2 lights and 2 filters and a heater. This means that you will have 2 – 5 devices that need to be plugged in.

Your outlet should be concealed inside your wall opening in one of the top corners. Make sure not to install it in the top center, it might interfere with the lights placement. Once you have one GFCI installed you can wire additional outlets off of it that will have the same properties (refer to the GFCI’s instructions). A second outlet in the opposite corner will be useful for larger tanks with extra devices.


Pros and Cons of wall aquariums

in wall aquarium

Wall aquariums are awesome but they also create some unique challenges. Here are the Pros and Cons for wall aquariums:


  • Aquariums look much much better inside a wall
  • Wow factor
  • You can look through the wall
  • Take up no floor space
  • Improves a rooms decor


  • Less elbow room for maintenance
  • Initial construction work (drywall and electrical)
  • Larger investment
  • Smaller fish

So wall aquariums look much much better than regular aquariums but there is more of an initial investment , less elbow room for cleanings and smaller fish overall.  Check out wall aquarium prices here:

in wall aquarium

Jumbo in wall aquarium

It’s ok, your aquarium can be deeper than your wall

It’s true a 5” or 6” wall aquarium can hold most pet fish species however, a bigger aquarium can hold more.  You can put a deeper aquarium in your wall by having one or both sides overhanging.  This can be done by having a base underneath 1 ½” thick and firmly secured to the wall studs below.  You will not need any additional supports as long as your overhang on one side doesn’t exceed 2”.  If you want one side to hang out more you will need to add some triangular/gusset pieces to support the base.