Opinions On Large Tank Placement Please

I have a situation where I want to put a large aquarium (roughly 8' x 4' x 2') in a room that is not on a concrete slab. I understand that it generally isn’t a good idea to locate an aquarium of this size on anything other than a concrete slab. This room I am talking about is an addition to the first floor of an old stone building. It was built by building the room over 2-3’ tall CMU blocks on a concrete footing. This creates a crawl space that runs underneath the entire area of the room/addition. On top of the CMU support walls there are 2x10 or 12 joists that run perpendicular to the CMU wall and create the support for the finished floor. It just so happens that one of these CMU support walls travels directly below where I intend to put an aquarium. This is why I thought that a large aquarium may work here..., but I'm not sure how large.

My question to MFK is….., based upon your knowledge….., Do you think an aquarium of this size would work in this type of situation. 500-600 gallons x 8 lbs./per gallon + the tank weight equals roughly 5,000 – 6,000lbs. Correct? How much would a 8x4x2 acrylic weight? Have anyone ever seen something like this done before?? I understand that I will most likely need to reinforce the joists below the tank. Possibly by screwing 2x4 or 6’s to the existing joists and even putting another support beam underneath the existing joists, running parallel with the aquarium and the existing CMU wall…., these additional support beams would be 2 feet on both sides of the existing CMU wall (basically underneath the entire area of the tank.., with the CMU wall running down the middle of the tank and the additional support beams 2’ feet away running down both sides of the tank. I’m just kind of on the fence as to weather this is possible and weather it is worth the hassle/head-ache??? If people don’t think this is worth doing…., can someone recommend a tank size that I would be able to get away with given this situation (the bigger the better) I appreciate anything you have to contribute about my situation. THANKS AGAIN for all of the help fellow MFKer's……….

Bud8Fan;1423008; said:

When in doubt, go overboard.

I sistered a few of the joists and built two beams supported by floor jacks for my 300.
Not only can I sleep at night knowing that my tank won't fall through the floor it will also eliminate floor bouncing when the kids are jumping in the living room.

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Wow that looks a lot like my basement. ha/ha. thanks for posting I thought about putting the tank in the house portion of my place as opposed to in the addition. But, I kept thinking that if some type of "accident" did happen that it would less catastophic if it happen over dirt (addition/crawlspace) compared to the basement where there is expensive equipment and utilities. I guess either one would suck horribly.

I guess a 300 gallon isnt to far off from a 500 - 600 gal. what are the dimensions on the your 300 gallon?? Its good to see that a larger tank can exist on something other than a slab.

I guess the only thing that I need is some help with figuring out a way to create the base for the additional support beams that I plan on installing. The problem is that there is only dirt below my finshed floor. So i'm not exactly sure what to use a a base to hold up these additional beams. Maybe just cinder blocks with 4x4 posts holding up the additional support beams. My only problem with that is if the blocks sink down into the dirt under pressure and thus dont support the joists at the height that i need..., will the whole system fail then. Maybe i'll need a compacted stone base bellow the blocks???

Anyone else with some ideas or projects like this that they conquered.??

I guess it will just take some serious supporting of the floor???

When I first started thinking about this I just kept thinking that I needed to see some instances where this was done to assure me that a monster tank could be put on something other than a concrete slab.

I'm confident in my structural knowledge and my designing/building abilities...., i work with this stuff all the time.

I guess the next question I need to ask myself is weather I want to do this in a place that i dont even own...... cost isnt really a problem..., I have tons of lumber laying around. Time is the only thing........

Bud8Fan;1423125; said:

Is there room in your crawl space that you can get in there and dig out holes to pour footings to place your jacks on?

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Barely....., its like 2-1/2' - 3'
Are you thinking that this is the only way to handle this??

I'm wondering if the fact that this existing CMU wall is actually situated directly underneath my "tank" that i may not need the additional support beams?? In your situation you didnt hava a main support beam directly under your tank. Atleast I assume. And this is why you had to make additional supports??? What do you think?? I guess it is better to be safe than sorry.., like you said. My "tank" is wider than yours though..., so maybe it will be needed???

I really am not looking forward to crawling under there because it is nasty but if it is needed then I will take care of business.....

Any other opinions???

Maybe I should just locate this tank in the original house so that way I would have space to work and there would be concrete for a base.....

Just not sure if that much water and weight is good in a old house with so many other things that could get damaged

WHAT TO DO!!!............, so many things to take into account......

Bud8Fan;1423125; said:

Is there room in your crawl space that you can get in there and dig out holes to pour footings to place your jacks on?

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What are the dimensions of your tank???

Thanks again Bud8Fan....., appreciate the help. I assume the jacks will allow you to tighten as you encounter any sag?? How much did you spend on these jacks??? these Dek-blocks seem to be heavier, glorified concrete blocks..... any idea on a price for these?? may just resort to CMU blocks......