Fish Aquarium Stand (40 Breeder Tank With Hidden Sump Door)




About: I graduated from Texas A&M University and I'm an avid DIYer constantly working on multiple projects and/or ideas. I thrive on efficiency and I'm always looking for better ways to do everything.

This aquarium stand was designed for a 40 gallon breeder tank on top, with a hidden side door to allow a 20 gallon long tank to be placed inside for a sump.  It was over sized a little to allow more room on the inside for an auto top off unit.

The goal of this aquarium stand was to be a pleasant size for both standing and sitting since this is located in the dining room / entry way.  The other concern was to make sure I could reach the bottom of the aquarium without any sort of step stool since I am only 5'7". In order to accomplish both of these, I chose the height to be 39" tall.

Sizes L x W x H (inches):
40 Gallon Breeder tank  -  36 3/16"   x   18 1/4"   x   16 15/16"
20 Gallon Long tank - 30 1/4"   x   12 1/2"   x   12 3/4"
Over all aquarium stand (without top trim) - 39 1/4"   x   21 1/2"   x   39"

Things to keep in mind:
When calculating the size for the stand, make sure to calculate for thickness of materials.  I used 2x2's, which is actually 1 1/2 inches thick, for the frame work. The Plywood for the outer covering was 3/4 inches thick.  Adding feet to the bottom of the stand will make it a little bit higher as well, 3/4 inch in my case. Also depending on how the frames are placed together will change the overall dimensions.

Step 1: The Hall of Frames

The design of the cabinet is to be able to hold a 500 lb tank on top and enough room and stability in the inside to hold a 225 lb tank and still have a nice appearance without being too bulky looking.

Four frames were built out of 2x2 material versus 1x2’s or 2x4’s.  The 2x2 material gives plenty of stability and holding power.  Plus they are a little cheaper and little lighter weight than 2x4’s.  It also allows for the needed space on the inside for the bottom tank.

The frames were stitch stapled together with three 1” wide x 1” long staples on both sides making sure the staples are flushed with a hammer if needed.  Also a 2 1/2  inch nail was used at each corner (picture 4).  When framing, try to keep each frame as square as possible.  This will help later when the frames are put together to form the base of the cabinet.  When laying out the frame work, the horizontal 2x2 is on top and bottom of the vertical 2x2's.  This gives more support due to the weight being distributed to the verticals instead of the fasteners.

Both sides are the same.  Cut the 2x2’s:
34 1/2”---4 each  (for the verticals)
19 3/4”---4 each  (for the horizontals)
This is for both sides.  As mentioned above, make sure horizontals are nailed on top and bottom of verticals. The overall side frames measure 19 3/4”wide x 37 1/2” tall.

Cut the 2x2’s:
34 3/4”---4 each  (for the horizontals)
34 1/2”---6 each  (for the verticals)
This is enough for both the front and the back. In the picture, the center vertical is not shown in the front frame, but needs to be added.  They are centered in the framework.  Nail the inside verticals with two nails each at top and bottom.  The overall frames should measure 34 3/4” long x 37 1/2” tall.

Step 2: The Full Frame

Once you have framed all four sides, it is time to assemble the base together.  Place a small bead of wood glue between framing members before screwing them together.  Use three inch screws at top, bottom, and middle—minimum. (Screws may have to be slightly angled to make sure they don’t come out the other side, due to the two pieces only being 3” wide.  If the wood tends to split too badly, you may consider pre-drilling a pilot hole for the screws.

Make sure  framing members are tight together with no gaps, because this will alter the overall dimension of the base cabinet.  Notice in (picture 2) , the side frames are screwed to the outside of the front and back frames.   This allows more room between framing members on the side( which will be important later when installing the tank) without making the cabinet any wider than necessary. After the base framing is complete, it should measure 19 3/4” deep x 37 3/4” wide x 37 1/2” tall.  Two 2x2’s were added to the top and to the bottom to help support the weight of the tanks.  They measure 16 3/4” each and are placed roughly 10”-11” apart and fastened on each end with two 2 1/2” nails.(picture 4) Scrap blocks were added (with three 2 1/2” nails) to each side on the top for extra support for the weight of the tank, because the actual tank will be resting on the plywood top and on the inside edge of the framing members.

While securing frames together to form the base, make sure the wood components are flushed to the outside of the cabinet. This will help to keep the plywood flush when nailing on later.  Also double check that the base is staying square.

Step 3: The Walls

Two sheets of 4’ x 8’ x 3/4” plywood is needed.  If a different thickness of plywood is used, the plywood sizes need to be adjusted. The sequence of the nailing of the plywood is important because we want to cover up as much of the plywood edges as possible.  Use a table saw if available.  This helps to have a clean, square, and accurate cut.  Visually layout the cut pieces on the 4x8---being sure the wood grain is in the proper direction and all cuts are capable of being made.

Cut sizes are:
Top---37 3/4” x 19 3/4”
Back---37 3/4” x 38 1/4”
Front---39 1/4” x 38 1/4”
Sides (2)—20 1/2” x 38 1/4”
Doors (2)—14 1/2” x 30”

All plywood is fastened with a pin nailer using 1 1/4” pin nails (or brads)  The actual length of the brad is about 1 1/8”.  Fasten about 4”- 5” apart.  Also use a small bead of wood glue between the plywood and the framing for more stability.  Be careful not to get any glue on the plywood, because it will show up when staining it later if not properly sanded off. More fasteners can be used if desired.

Inside Bottom Plywood
Use the remaining plywood left over. It is not large enough to be flush to all the edges, but will be on the inside and unseen anyway.  You will have to notch around the 2x2 framing.  Use a jig saw to make it easier.  Details are talked about later.

Sequence of Securement:

Attach the top first. It should be flush with the framing all the way around. 37 3/4” x 19 3/4”

Next attach the back.  38 1/4” x 37 3/4”  It should be flush with both sides of the framing and with the top of the plywood on top (picture 4&5). This leaves the plywood edges to the back.

Next attach the two sides.  20 1/2” x 38 1/4” each.  They should be flush with the front framing and overlapping the plywood edges of the back.  It should also be flush with the top of the plywood on the top (pictures 6&7).
Only plywood edges that are now showing are on top and two front corners (which will be covered up later with trim)---the back doesn’t matter.

Next install bottom plywood in the cabinet. In order to get the plywood flush to the rest of the plywood, notches need to be cut out.  Place the plywood inside and mark where the 2x2 framing is at.  You will notch out four corners and at two center braces (pictures 8&9)  Pull out the marked piece of plywood and cut the notches out with a jig saw (picture 10)  Since the plywood for the bottom is what is left over from cutting the other parts, it is more narrow than the depth of the cabinet.  This is OK because it won’t be seen anyway---It saves from having to buy more plywood.  The depth of the notches need to be adjusted for this reason.

The last piece to attach is the front. (39 1/4” x 38 1/4”)  It should cover the rest of the plywood edges—leaving edges on the sides and the top only.  I used a solid piece of plywood for the front and cut out openings for the doors. I did this mainly because I wanted the grain to match and not have any splices in the plywood.
You should now have a fully enclosed box.

Step 4: Doors

Overall door sizes are 15” x 30 1/2”(This includes the corner trim width). The openings for the doors are 12 1/2” x 28 1/4”.  To cut out the openings, make a line at 4 1/2” and at 17” from each side of the cabinet and mark another line at 5” from the top and 5” from the bottom.  This will be the rectangle you cut out for the doors.---Verify that the openings will be 12 1/2” x 28 1/4 and look uniform.  Drill a small hole inside the rectangles so you can fit a jig saw in place to cut out openings (pictures 9&10).

This door is added for easy access and removal of a 20 gallon sump inside the cabinet which is 30 1/4” x 12 1/2” x 12 3/4”.  It will not fit through the front doors due to the center framing.  This opening can be on either side (which ever is convenient and practical for you and your sump setup)  The design of the hidden door is for easy sump removal without the cabinet looking too tacky with cuts and hinges showing on it  After the opening is cut out, the door will be flush mounted. A picture frame type trim will be placed around it to hide the cut out and look like a solid side with decorative trim.  A second picture frame trim is added on top for a more uniform look This is done on both sides of the cabinet---All trim is done later.  The door opening will be 14 1/4” tall and 14 1/2” wide.  Measuring  3 5/16” from the front and the back and 3” and 17 1/4” from the bottom, draw a complete square to be cut out with a jig saw.  Drill two holes on opposite ends for the jig saw blade to fit in, but not bigger than 1/2” because the cut out will be your actual door and the drilled hole will need to be covered with trim later (pictures 1&2).  Cut  as square and straight as possible.  From each drilled hole, you can make a good cut without turning the blade allowing a square opening and square door (picture 3).

Cabinet latches were used to connect the door instead of visible hinges (picture 4&5).  This made for a better looking appearance.  Two pieces of 2x2’s were secured on each side (near center) of the opening. These  blocks are used to fasten the latches to.  The 2x2 material had to be trimmed a little on a table saw to keep them from sticking out past the opening (which would make the opening tighter for the sump to fit through). (picture 8)  The roller parts of the latch were fastened to the 2x2 blocks.  The male end part of the latch was fastened to the door. Once the roller part is slightly secured, the male end can be pushed into the roller part.  Then set the door on top of the opening, making sure it looks square and even around the opening.  Then from the inside of the cabinet, pencil mark for the screw holes where the male part of the latch will be secured on the door.  Then pick up the door and secure the male part.

Stopper blocks were added to keep the door flush and to keep it from rocking back and forth.  Scrap plywood was used in areas where it fastened directly to plywood.  Trimmed 2x2’s were used on the sides.  Notice stopper blocks only stick out about 1/4”.  This allows opening to stay as large as possible for sump to fit through (picture 8). 

Press the door down into place and adjust and tighten roller part of the latch, making sure the door is still flush.

Step 5: Trim Work

The decorative trim for the side of the cabinet (including the hidden door) is 1/2” wide and has rounded corners.  This is wide enough to hide the gaps and the drill holes.  Wider trim can be used if desired.  It is a flat trim (not a corner trim).  Cut the trim on a miter saw with 45 degree corners and form a picture frame.  The over all length of the trim is cut to 15 1/4” for the tops and bottoms and 14 5/8” for the sides.  These lengths can be adjusted if needed.  The trim is placed around the door making sure half of the trim is fastened to the door and the other half over hangs the door and will cover the gaps.  Use wood glue to attach the trim to the door.  Place something flat and heavy on top of it to hold it in place while the glue dries.  Clamps can also be used.

After the glue is dry, small nails from the backside were also used. (picture4)—these probably were not needed.  Put the hidden door in place.  The top picture frame trim can now be glued and tacked in place.  It should match the door trim and look uniform.  The picture frame edges should be about 3” from the sides and 2 3/4” from the top. (These may need to be slightly adjusted.)  After it is dry, flip the cabinet to the other side and glue and tack trim on the same way, using the same measurements and methods.

For the front doors, use 3/4” corner trim around all edges.  Cut the corners at 45 degree angles on a miter saw.  The overall length of the trim should be 15” for the tops and the bottoms and 30 1/2” for the sides—CAUTION—Since all trim is not exactly the same widths, these measurements need to be verified, making sure they fit tightly around the doors and the 45  degree cuts are tight together.  Adjustments can be made if necessary.
( NOTE: The actual door size is 14 1/2” x 30”.  This means that  the INSIDE or SHORT END the 45 degree cut on the trim will be the same.)  Once measurements are verified for fit, apply the glue, clamp in place, and let dry.

One inch corner trim was used to cover the two plywood edges on the front corners of the cabinet (picture 8).  Two pieces 38 1/4” long are needed.  Glue, clamp in place, and let dry.

Step 6: Feet

The feet were used from the scrap plywood.  They are 2" x 2" squares that are nailed into the bottom of the frame.

Step 7: Top Trim

The top trim was made out of 2 x 3's. The easiest way to do the trim is to set the tank where desired. Then draw a line with a pencil around the tank for the placement. Cut the 2 x 3's to 41 1/4" for the front and back, and 23 1/4" for the sides. Once they are cut to the right length, use a miter saw to cut the ends to a 45 degree angle. If everything fits around the tank and the corners are good, fasten the corners together with nails or screws. Once you have the whole top trim together fasten it to the stand.  Nailing or screwing the trim from the top down to the stand is the easiest way to secure the trim. I did not want to see the nails / screws so I screwed the trim to the stand from the inside of the stand. One or two screws on each side is all that is needed unless it will be used for lifting the stand.  2 1/2" screws were used and started from the inside frame into the top trim. 

Step 8: Circulation Fans

Two equally sized computer fans were added in the back of the stand. The purpose is to help keep the sump at room temperature. The fans were wired (parallel) to an old phone charger that was rated 4.9V and 450 mA output.  The easiest way to explain this without going into too much detail is connect the positive wire from both fans toghether to the positive wire from the charger. Then connect the ground wire from both fans together to the ground wire from the charger (see picture 2).
WARNING: Make sure the positive wires do not touch the ground wires when it is plugged in. 

If the fans are connected this way, both fans should spin the same direction.  If opposite directions are desired, either flip the wiring on one of the fans or just turn the fan around when attaching it to the stand. Solder the connections together and wrap it with electrical tape.

The fans can be placed anywhere, but are 6" from the sides, and 11" from the top. Trace the fans onto the back of the stand where desired. Drilled two holes into opposite corners inside the square (picture 3), and cut it out with a jig saw the same way as the sump door. Make sure the fans fit and take them out until after you paint / stain.

Once done staining, glue fans inside the stand using wood glue.

Step 9: Painting

To help protect the wood from water spills that might happen and hopefully allow the plywood to last longer; Kilz was used to paint the inside white. First apply 2 coats and then stain the outside of the stand (next step). Stain might get spilled on the inside of the stand and will need to be painted over with a third coat.

Step 10: Staining / Polyurethane

3 coats of stain and 4 coats of polyurethane were applied. If the doors are attached to the stand, take them off and take the sump door off. Staining / poly gets messy, so grab disposable gloves and a plasic tarp to protect the floor. 

Sand the whole stand with a 150 grit sand paper prior to staining. If the 2 x 3's for the top trim are rough, use a lower grit sand paper to get it as smooth as possible. After sanding, wipe everything down with a clean and dry rag to remove dust.

Use a foam brush to apply the stain on the stand.  Desired darkness of the stain will determine how long the stain sits on the wood and how many coats are applied. Just make sure when applying the stain, go in the direction of the grain of the wood, applying evenly, and use one continous motion accross the wood. Apply a liberal amount of stain to one side of the stand and allow it to sit for 5-15 minutes. The longer you wait, the darker it will. (Note: Do not let excess stain dry on wood) If you are unsure how dark you want the wood, use a scrap piece of the same material to test it out. After 5-15 minutes wipe the excess stain off with a clean rag in the direction of the grain and repeat the above steps to another side until all sides and top are finished. Allow the stand to dry for 4-6 hours. Weather conditions will affect the drying time, so letting it sit overnight is the best. Once the stand is dry, use the steps above to apply a second or third coat of stain to make it darker if desired.  Once satisified with the color, allow the stand to dry for 8+ hours.

Once the stand is completely dry, add the first coat of polyurethane. Use a brush and apply a light coat.  A little polyurethane goes a long why when coating. The more that is applied at once gives a bigger chance to get air bubbles and not be as smooth of a finish. Allow the polyurethane to dry longer than reccomended to make sure it isn't sticky / tacky. After each coat is dry, use a 220 grit sand paper and lightly sand over the entire stand.  Remove any bumps or areas that are uneven. Wipe the dust off with a clean rag and repeat these steps until it has a solid smooth coat.

To allow the doors to dry faster, make stands out of scrap wood and nails (picture 8). The purpose of this was to be able to stain / poly both sides of the door at one time and allow it to dry on the stands. Stain the back side of the door first, then flip it over and rest it on two of the stands to allow staining of the front side. If the nails are sharp they can put small dents in the wood so be careful about that.

Step 11: Plumbing Holes

For the drain and return pipe to and from the sump I got a local fish store to drill two holes in my tank.  After the holes are cut simply set the tank on the stand and mark where the holes are at. Depending on the size of the holes cut, use a hole saw large enough to drill the two holes and allow the plumbing in the top of the stand.

Step 12: Finished

Final step is place the doors on and any handles / cabinet locks. My cat thought it was a new playground and had fun in and out of the stand.

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    21 Discussions


    3 years ago

    Ik it's been a long time since posted but where did u drill the holes in the tank looks like the bottom if so how to u drill them without making tempered glass

    1 reply

    Reply 3 years ago

    I actually had a local fish shop drill the holes in the tank and they are on the bottom of the aquarium. I placed the tank on the stand and used a sharpie to draw where the holes should go. I don't think tempered glass can be drilled.


    4 years ago on Step 12

    you didn't talk about the plumbing or sealing those two holes you cut in the tank - that is what I was most interested in for this build - but I guess this was about the stand. and links for that work: pump used, how to water tight seal those supply / return hoses, what you are using for circulation in the tank?


    1 reply

    Reply 4 years ago on Step 12

    To seal the holes in the tank I used some reef bulkheads that were purchased at a local fish store. For the overflow I built a durso standpipe.

    For the return I just use some flex tube that fit the return pump, and I'm using an Eheim 1260 return pump.

    Inside the aquarium I use 2 Hydor Koralia 1050 power heads.


    4 years ago

    I know its been quite a while since this was posted, but it would be cool to see the finished set-up going. I'm to the point of waiting on my plumbing parts and pump to be delivered and am curious as to how yours worked out.


    5 years ago on Introduction

    I am trying to build this but I am having a lot of trouble finding the 1"x1" staples. I looked at Home Depot and Lowes but all they had were the cable staples none of which had these dimensions. The closest I could find was the 13/16"x2.5" staple (clearly too long). Any thoughts?

    1 reply

    Reply 5 years ago on Introduction

    The staples are not really required, and are only used to help each side become more secure on their own. This can be achieved with anything really...nails, brads, screws, glue. The main thing is to ensure that the entire frame (all four sides) does not move too much once fully constructed. Even if it has a little wiggle, it will become completely solid once the sides are applied. If the staples are hard to find, I wouldn't worry about using them. They provide no real support, and were just used because I had them lying around.


    5 years ago on Introduction

    I have been trying to find someone with a guide for a stand for a 40 breeder for awhile. I am glad I was able to find this. I have had both a 40 breeder and 20L sitting in my office for 3 months now after buying them during the 1$ tank sale. Thanks for the great guide! I will be buying the mats in the next few weeks and let you know how it turns out.


    5 years ago on Introduction

    Nice job but I'm confused as to why you need two tanks. Is this a salt water setup? I'm ignorant about salt water aquariums...

    1 reply

    Reply 5 years ago on Introduction

    Yes, this is a salt water setup. One main reason you have a sump (bottom tank) is you can hide all of your equipment (protein skimmer, heaters, additional filtration). It also adds more water to the entire system so the parameters are less likely to have major changes.


    6 years ago on Introduction

    This is awesome, when I move I may make something similar for my axolotl; my male and female bettas, my zebra danio. As well as another structure for my cousin's betta; and my aunt's fish. Thank you for some inspiration. :)

    1 reply
    broken board

    7 years ago on Introduction

    Nice Job!

    Were you going for the ply wood effect or more the nice brown stain?

    MDF is more expensive but the finish is tenfold vs. ply wood.

    I’m a fan of MDF finishes, but as a whole, unless I’m using it for a super flat glossy finish will avoid using it.
    I like to sand like a mad man and love the finish of hard wood.

    I’ve received a bit of feedback on my latest job about commercial grade ply wood bending and warping, have you experienced that yet.
    Being in a humid environment should increase that effect.

    If so how did you overcome it?

    2 replies
    d00dybroken board

    Reply 6 years ago on Introduction

    It has been almost a year and still no warping or anything... looks just like it did day one.

    d00dybroken board

    Reply 7 years ago on Introduction


    I like the way plywood looks, and I have never tried MDF for a project like this.

    The stand is still in its early stages so no warping yet, only time will tell.


    This is a beautiful piece of furniture! I think the fans built into it are a great idea. They will help keep the enclosed space from getting too humid and mildewed.

    1 reply

    7 years ago on Introduction

    Maybe I can show this to my husband and he will make it for me :-). Thanks!


    7 years ago on Introduction

    Where do I get one of these? This is spectacular. I wish you were near me so that I could purchase this from you. It is exactly what i need in my entry way!