Spread the weight out. shim this support fully. test for level with the tank partly, wholly filled.

120 gallon tank on 2nd fl, stand and tank/weight on floor concern 4/9/13

Hi WWM crew,

Hey Audra

I have4 — 10+ inch ID sharks housed in a 55 gallon aquarium. I am like many that did not do my homework when I bought these loveable fish but I love them and cared for 2 of them for the last 13 years, the other 2 for 6 years. They are happy, eating well and my tank parameters are excellent. They are way over due for an upgraded tank but all I can maybe manage is a 120 gallon.

. well, the bigger the better

The plan is to place the tank in my office, very low foot traffic, the floor is wood and covered with linoleum, against an outside wall and would cover 48.5 length x 24 inch deep. I live on the 2nd floor of a 100 year old house.

Mmm, DO spread out the weight of this system at least. by placing a thick/ish piece of plywood under all legs of the stand, leveling same w/ long wedges to do the same

Right now, the room where they will go has 3 aquariums in it, which have been set up for well over a year: 2 — 30 gallons stacked on a double stand and a 40 breeder. These tanks will go if I move in the 120 tank.

What are your thoughts? Can I get away with adding such a large tank in this space?

You should be able to. think on the weight per square inches, feet of humans standing on this floor. MUCH more than this tank per unit unit. I would have someone qualified look underneath the floor (crawl space) to check the supports. You may be advised to add a bit more here. or to move the tank a bit in one direction

I use to have 8 tanks running in this apartment but Ive downgraded to 6. After Im done upgrading all my tanks, I hope to just have 5, a 120, (2) 55s, (1) 40 and a 30.

and the files above. Bob Fenner

Question about weight 5/21/12

Hello WWM team,

Hello Al

I have (2) 30 gallon tanks on a double iron stand. The stand sits on ¾ in plywood on my carpeted floor. Its been set-up for the last 2 years against an outside wall (of the house). Now, Im planning to replace these tanks with (1) 55 gallon tank.

I live on the 2nd floor of an 80+ yr old house. The area where the tanks are is the most level area of the room, carpeted over hardwood floors. The floor does have a slope towards the middle of it and is perpendicular to where the tanks rest. Im nervous to have a 55 gallon tank on a carpeted floor; however, I will be placing plywood under this as well.

My question: Which is better in your opinion, the weight of the 55 gallon or the (2) stacked 30 gallon tanks on a floor like mine?

The 55 would be better as the weight is distributed over a larger area.

I do have renters insurance so my landlord is ok with my set-ups. I have 8 tanks spread out in my apartment.

Good to have renters insurance. Back in my early days of aquarium keeping, I had a 30 long split open on

a carpeted floor and I lived in a third floor apartment in a brand new complex. Bad thing was is that I wasnt home when it happened. I need say no more.

Your thoughts?

As above. James (Salty Dog)

30 gal tank on a radiant heat floor 2/17/12


Hello Cyd

We have a 30 gal glass Oceanic tank (12 x 36 x 15) on a wood stand and we are considering placing it in the center of a 13 span in our family room.

It is a new build with 2 x 10 joists on 16 centers.

The hitch in all this is the porcelain floor has wiring for radiant heat throughout.

We are planning on putting 2 support columns under 2 of the joists to carry the weight and prevent any sag that could crack the floor and thus damage the heating cables.

Any input regarding this amount of weight on such a floor would be greatly appreciated.

I would contact the installers and/or manufacturer of the system for their advice before doing this. I personally do not see a problem providing the stands legs are not sitting directly on a corner of a tile where it could chip from the weight.


Ditto. James (Salty Dog)

Re 30 gal tank on a radiant heat floor 2/17/12

Thanks for your input.

Youre welcome. James (Salty Dog)


90 Gallon Reef Aquarium on a 2nd floor apt 12/21/11


Hello Gregory

I have been reviewing the site a lot, and have found a lot of good information, but I am still curious about my setup and would like some feedback to either make myself feel more comfortable or avoid an unfortunate mishap.


I have a 90 gallon reef tank 48 3/4 x 18 1/2 is the base measurement, and the tank is a 48 x 18 x 25..I have it filled up with about 1 to 1 1/2 of crushed coral for the base and roughly 20 large pieces of base rock, with upwards to 25 frag size pieces. I live in a second floor apartment and have the tank positioned over an interior wall, the wall is continuous and goes down the basement floor, which is concrete.

Sounds good so far

The wall is constructed of 2x4s, and the floor joists are 2x8s (not true 2x8s) and run front to back to the tank or perpendicular, with 16 OC spacing.


I am curious if my apartment is going to crash in on my downstairs neighbor or not?


I am extremely worried especially since my 2 year daughter wont stop jumping right in front of the aquarium, because she sees Nemo in there and cant hold in the excitement.

Heee! Tell her she can jump all she likes, you could not have positioned the tank any better than you have. 2 x 8s running perpendicular to the tank would hold a bigger tank than yours, especially if there is a wall underneath

I look forward to your response!

You have it Gregory. Of more concern to me would be the potential flooding of the downstairs flat during a power outage or accident. I would concentrate all your efforts on making the system as flood-proof as possible if you have not already done so!



Re: 90 Gallon Reef Aquarium on a 2nd floor apt 12/24/11

Hello Simon, Thank you for you quick response.

No problem Gregory!

I really appreciate it, I already feel better, however, I did just notice that the wall the tank is up against is not the exact wall that runs to the basement floor. After taking some measurements, It looks like the wall is about 1 to 2 in front of that basement wall. It is not directly above it nor is it tied into it. So, my tank is actually sitting out about 1.5 from that basement wall, is this something to be concerned about.

Not if you have it on 2 x 8 joists. With a 16 OC spacing you could do your best to ensure that the tank sits on four of the joists, not just three

My next question for you Simon is, how do I prevent against flooding? I have two canister filters and a hang on the back protein skimmer.

Oh. Do you need these canister filters? Most all of the filtration in your system should come from the live rock itself, really the canister filters should not be required at all. The skimmer is a problem, and the most likely to flood, but not during a power outage, more likely from overfilling/ leaking some time down the road.

My UV sterilizer is in the out line of one of my canister filters. It seems the only access the water would have to get out would be through the filters, how do I set them up to prevent flooding during a power outage?

Take them off line. Perhaps the UV as well. You could think about upgrading to a system with a sump. A large enough sump should collect all water in a power outage, and many things like skimmers, reactors can be placed inside so if they leak they just leak into the sump and not on the floor.

Thank you Simon!

No problem!

I will watch Finding Nemo with my daughter tonight and tell her to go to town with the jumping!



65 Gallon On The 2nd Floor? — 10/25/11

Well I finally got the 65 gallon tank that I was after! However, when I look at the tank, its pretty large and when you calculate approx 8 pounds per gallon for a 65 gallon you end up with about 520 pounds (I know that water isnt really 8-lb per gallon but I like rounding up). Not to mention the tank, and stand and substrate +rocks decorations and hood! So lets put it at 800lbs total.


The tank is 4 ft long and width and height I still must measure.

Whats pertinent here is the footprint of the tank/stand

The house is about 20 years old and I am in the room above the kitchen, and my room is next to a wall that separates it from the bathroom, however the wall from the bathroom does not extend downward through the kitchen.

So not a load-bearing wall

From my door to window (opposite sides of the room) is the direction the joist splices run. basically just dont want to wake up with a hole in my floor and 65 gallons of water in the kitchen. but will I be able to keep my 65gallon in my room on the 2nd floor?

Likely so, though placing the tank along an outside or otherwise load-bearing wall is best

I do have one wall that continuously runs all the way to the basement.

Then I would suggest placing the tank along this wall

I know theres a lot of information left out but was just wondering what you might advise. Im really paranoid right now.

The 65g tank placed along a load-bearing wall should be just fine (have seen tanks twice this size re)but for absolute peace of mind, I suggest you consult with a structural engineer (can be found in the phone bookand will likely charge an hourly fee to come out and provide you with an assessment).



Tank BuildStand/Floor Support — 09/15/11

Im thinking of upgrading my tank and have a few questions I need clarified before going forward.

Lets see if I can be of assistance

First of all I was looking at building my own stand.


I came across this DIY project and would like to know if this will hold a 90 to 120 gallon tank. DIY Oak Aquarium Cabinet, Do It Yourself Oak Aquarium Cabinet Its made of plywood not the 2 x 4s I have seen on a lot of other stands. Is this a safe sturdy design for that size tank?

Likely so The furniture-grade Oak plywood that would be used is very strong. As long as the joinery is sound, plywood could be used to support a very large systemgiven the proper design

I have read on your site that there is not a problem with most floors and a 75 gallon tank.

As a general rule, yes

How about a 90 or 120.

Unless the structure is very old or otherwise damaged, this too should not be an issueassuming the tank will be placed near an exterior wall (the floors are generally stronger here). I have a friend who had a 120 on the second floor of his home for years, with no issue. But the house was also of fairly recent (less the 20 yrs. old) construction

I am working on pictures, measurements, etc. for a more detailed question,

Ahvery good

however, my technology is not cooperating right now. I currently have a 90 in an adjacent room with similar flooring joists. Is the 75 gallon about the limit of most floors?

Nobut as indicated, much depends on the construction (size and spacing of the floor joists) and age of the structure. But if there is any doubt, the couple hundred bucks spent to have a structural engineer come in and take a look is well worth the peace of mindand is also of great assist should something happen and you make an insurance claim. I have a 500g (en toto) system that runs perpendicular to the wall and is consequently, parallel with my floor joists. Having an engineer come out to inspect and approve (in writing) both my DIY stand and the added floor supports under the house was a huge comfort. Best $140.00 bucks spent on the whole systemand a drop in the bucket by comparison [grin]

My current tank has a deep sand bed that is two years old. Reading in several places I have seen some use all the sand in a move and others use just the top layer. Should I just replace the sand bed?

Up to you But as a cost saving measure, you can save-off the top inch or so to re-seed the bed, and just rinse and re-use the remainder

I plan on reusing my live rock, skimmer, pumps, water, etc. How much of a cycle will that cause?

Likely not much, if any (do monitor closely)especially if you rinse the bulk of the sand before reuse, rather than just transferring all which mixes layers/kills biota

The tank will be transferred into the new one all at once. I wont be able to leave my current tank up and running while changing to the new tank as I am using a lot of the equipment from the old to the new.

Is done all the time You should be fine, but do keep a close eye on things for a whileand be ready with large water changes, if needed

As always thank you for your help.


A pleasure to share, as always EricR

Re: Tank BuildStand/Floor Support 9/19/11

Thanks Eric.

Quite welcome, Sarah

I decided to use the 2×4 frame. It will hold for sure and really is looking nice.


Now, the placement of the new tank. My current 90 is parallel with the joists and no problems for the last two years.


The new stand is quite a bit heavier. I have two places that I can put this tank. The placement I would like is about 4 feet from the outside wall and the joists run parallel to the tank. In this spot I will be able to plumb the sump into the basement in the future.

I see

The other spot is perpendicular to the joists but in the center of the house. This is also where the steel beam is.

Ahno problem then, I would estimate

I will not be able to add any supports down stairs because it is in the middle of a finished kitchen and bathroom in the basement. The joists are 16 inches apart and are 10×2. The house is 20 years old.

Additional support is likely not needed here

My husband does not think we will have a problem with the first placement

I would agreethe modern construction coupled with the joist size should be able to handle this static loadin my humble opinion. I remember keeping tiered 55g setups (110g en toto) in much older housing, several decades past

but never hurts to ask someone who has been in this hobby longer.

About 4-decades now [grin] Plenty of disasters in that timebut no tanks through the floor!

What do you think?

I do not foresee a problembut do watch for excessive bounce in the floor when you walk by the tank, once the system is in place. EricR

Can My Floor Support My Tank? — 04/08/11

Good day to everyone in WWM!

Greetings Vince!

I live in the 3rd level of an apartment unit with concrete floor. The floor is about 5-6 inches thick (based on the thickness of our corridor floor outside). The apartment was built in 70s. Im in Australia by the way where building codes are different from the US and Im really not familiar with the Australian building codes.

If anything like here in the States, the codes can/do differ widely by state and countyeven city

I tried searching the internet regarding building codes in Australia but I cant really find a definite answer

Can be difficult to find and obtainsometimes requires the purchase of a pricy code book

and hiring a structural engineer will really be my last resort.

But is your best/safest optionand this is assuming the apartment complex itself allows aquariums on anything but the ground floor

Currently, I have a 180-litre aquarium (about 50 gallon if my conversion is correct) but wanting to upgrade to a 425-litre (112 gallon) Will this be a problem? I read in one of the posts here that concrete floors can hold approximately 250 pounds psf.

That probably is a good general guide for a static-load, but this is not a set requirementthe load bearing of a concrete floor will differ (sometimes by a wide margin) based on the minimum code requirements for the particular structure type in a given location

Also, I am placing the aquarium in the corner where one of the walls is a load bearing wall (Im assuming it is load bearing since it is the outer wall) and whether this will make a difference or not.

Placing the tank next to an outside wall is likely one of the stronger locations in the room, agreed

Would appreciate any helpful advice.

If the apartment rules allow, then it is likely safe to place this tank (Does the apartment allow waterbeds on upper floors? If so, this would be a clue as to the strength of the floorsthough not allowing could simply be a water damage issue). But my opinion does not protect you if I am wrong. At the least, you should probably contact the local building permit office and talk to a building inspectorat best, contact/contract a structural engineer to take a look and advise. The couple-hundred bucks it will cost to do so will provide a wealth of assurance/peace of mindor at least a concrete reason as to why its not advised



Good luck mate EricR

Question about aquarium stand 12/6/10



Ive been reading your site, but would really appreciate a little clarification with something. I recently acquired a 75 gallon tank to replace my current 30 gal in a second floor room. Now, Ive looked at the

floor plan and have placed the aquarium in a position where it is perpendicular to the floor joists and Im assuming the floor will hold the tank (the 30 gal has been in the same spot with two bookshelves on either

side for years with no issue).

A 75 will not have a problem either under any building code I am aware of in the US.

My problem is with the stand; It is a metal stand, and I am very wary of placing this heavy set up on a 4 legged metal stand. According to your FAQ, this can be remedied by placing a piece of plywood under the stand to create a base to more evenly distribute the weight. My questions: How thick should the plywood be?

1/2 will do, but I personally would go 3/4 to make the base a more solid, whole piece.

Should I use shims, and if so, how many?

However many and wherever it takes to level the tank. See:

Thanks for any help here!


Welcome, Scott V.

Tank Weight On Concrete Floor 8/14/10

Hello, WWM Crew:

Hi Steve

Thank you for this site and your efforts!

Youre welcome.

Ive read through your FAQs about Stands, Supports for Aquariums: About Floors, Flooring Underneath and I think Im going to be OK, but I would certainly value your opinion.

This will be my first large tank setup.

I live on the 2nd floor of a 3-floor, 7 yr. old condo, constructed with concrete flooring — probably at least 4 thick, Im told. I would like to setup a 120 gal. acrylic aquarium (48x24x24) against one wall: one wall

is load bearing, or, the other is app. 3 out from a load bearing wall (a closet wall underneath the stairs). My wood stand is 51 x 26 (app. 165lbs.) and rated for 2500 lbs. I may put a 5/8th sheet of plywood under the stand — couldnt hurt to help with leveling the setup?


Im told that concrete can bear app. 250 lbs. per sq. ft. — but I dont know at what thickness that is. If my thinking / math is correct and if Ive learned anything from your site, I think my pad area can support app. 2300 lbs. total: app. 9.2 sq. ft. of stand base x 250 lbs. per sq. ft. = app. 2300 lbs. weight bearing. Allowing 10 lbs. per gal. I think the tank, stand and equipment might total. 1400 — 1500 lbs.

Does this sound correct to you?

Mmm, close. The water alone should weigh somewhere near 900 pounds.

I would rest your fears, your floor should be more than capable of supporting that weight.

Thanks again for helping.

Youre welcome. James (Salty Dog)

Regards, Steve

Tank, weight, floor concern — 8/10/10

Hello all,

Hello Brad

I am in the process of setting up a 40 gallon breeder aquarium.


I have the tank sitting on a solid wood stand with double 2x4s running around the base. I have shimmed the stand using a 1×4 at one end to make everything level. I was originally planning to use a 20 gallon refugium

below the tank but I am now thinking a 10 gallon fits better.

Bigger is better, but you need to allow yourself room to manoeuvre. 10 gallons is ok for this size display

In addition, I have a EV-120 skimmer and canister filter that add to the overall weight. I am a bit concerned about the weight. My building was built in 1966 (brick and concrete) and I live on the 10th floor.


The tank is sitting at the corner between an external wall and the wall between living room and bedroom. I am probably being paranoid, but should I worry about this punching through the floor?

I would check to see what the floor is made of and find the joists if there are any. If you have wooden or chipboard flooring on top of joists then the tank will need to sit across two at least, preferably more, of them. If it is not, then the tank could easily sink, especially if you have a leak. If you have concrete flooring then you will be fine. I would be very careful re: setting up of this, research on WWM, make sure you have drilled holes etc. for the drains, as you could be liable for any water damage to the flat underneath.


No problem Brad



Aquarium weight concerns 6/3/10

Hey Bob & WWM crew,

Hi Josh

As always I have scoured the net and WWM to find an answer, and I am now more thoroughly confused than ever. So, heres the long and the short of it. I own a 250 gallon hex aquarium. I built a solid 4ft X 3ft stand for

said aquarium. Wife wants it upstairs, yes upstairs in the bedroom. So, Ive read a newer (within 10 years) home can hold 250lbs psf. Is this true?

By using the 10LB per gallon rule am right at 2500 lbs at 12 sq ft. Am I pushing it here. Would you do it?

Youve got the weight of the aquarium right. Building codes vary from town to town, so its hard to say what your house was built to support. It could be as low as 40lbs psf. Putting the tank on the second floor sounds like a bad idea to me. If you did do it, put it right next to a wall which has walls below it that go all the way down to the basement floor. Add a few columns in the room below the tank, and then in the room below that. Then, it might not ruin your house. Although, the columns would sure bother the wife. Why not put it in a common space though, so its beauty can be shared by more people?

Thanks for all the help over the years.


Hope this helps, Scott T.

Tank V.S. Floor 5/13/10

Hey WWM,


I was wondering if anyone in your staff had experience with a large tank set-up in apartment buildings or anything that is not on the ground level.

Oh yes

I have recently purchased a tank with a surface area of 26×48 there are about 100 lbs of live rocks, 100lbs of sand, 1010 gallons

Mmm, no. unless this tank is amazingly tall. there are about 7.5 gallons per cubic foot, 231 cubic inches or so per gallon.

of water + 30 gallons in the sump in acrylic tanks, a base that weighs about 130lbs. Im estimating a weight of about 1500-2000lbs which will be dispersed over 8.5 or so sqft meaning that each sqft should be able to safely hold a minimum of 250 lbs. I have a 55 gallon that, according to the same estimates is safely holding about 190lbs per square feet. My girlfriend and I are living on the 6th floor of an apartment building and she is scared that we would kill our downstairs neighbors (wouldnt be such a bad thing) and we live in a NYC building. I was wondering if anyone had any experience good/bad with similar (or larger) size tanks in apartments or if you had any advice on how I could safely test the strength of my floor.

When, where in doubt, Id check w/ your super. and spread out the weight w/ wood under all the legs. Read here:

and where youll lead yourself via links

On a related note, we currently have a tank with ich in it. it is a 55 gallon with only 1 lonely puffer (who is feeling much better lately). It has some live rock that is housing a lot of critters and about 60lbs of sand

that Id like to move over to the other tank. Im worried about bringing the parasites to the other tank, is there any logistical advice you can give me for making this move short of disposing all of my water,

re-curing/cleaning my live rocks and sand and keeping my puffer in another container until he is better?

Mmm, yes. the usual quarantine procedures gone over here:

the first tray

Thank you,


Welcome. Bob Fenner

How to Calculate Max Weight Limit? 5/2/2010

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