Large Tanks and Structural Support

The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.

AquaAddict

Aquarium Advice Newbie
Joined
May 4, 2003
Messages
5
Location
Findlay OH
What is the largest sized tank I can have without worrying about adding structural support to the floor? I suspect this would be about 75-90gallons. I have heard many people reinforcing the floor on 125+ gallon tanks.


Thanks,

AquaAddict
 
It would kind of depend on the building and the location of the tank.

If you position the tank so it is sitting only on one floor joist then you would be advised to reinforce the floor with a smaller tank than if you positioned the tank so the weight was being distributed over several floor joists.

The closer to a load bearing wall the tank is the larger you can go with out reinforement.

Have you established the location of the tank and how the floor joists run under that location? Is the location clsoe to an outside or inside wall? What level is the tank to be located on?
 
I just went through this with my new 125g tank. I was putting it kiddy-corner to two load bearing walls (the outside corner of the house)

looking in the basement -I saw that the 2x11 support beams were running in parallel to the tank (ug!). Back upstairs, I located where along the floor the two beams were running, and moved the tank out from the wall such that the weight was evenly supported by the two beams.. (I had initially set it down closer to the wall, in which case it would have only had one support beam running down the center of the length of the tank.) Yes, this meant the tank was farther out from the wall than I wanted, but it's actually nice being able to get in behind it..

Anyway - the support beams are 16" apart from center, and the tank+stand is approx. 19" deep, so I just centered it over the two beams.

This *probably* would have been ok.. but I was looking around the local hardware store, and they have the floor jacks for $16 each, so I figured "eh, grab two, a cheap insurance policy".. I placed them in the basement, one under each beam (I think they support 14,000 lbs or such.) and placing them there gave me a great deal of comfort..

125g of water weighs approx. 1000lbs, plus the tank and stand and rocks/gravel we're looking at at least 1600lbs, over an area of ~12sq/ft.. better safe than sorry.

Also - be sure that you don't do what I did and check that the tank is level before filling it up with water.. Get some of those composite shims (sold alongside the wood shims at your local hardware store, only they are much stronger) and shim up one side as necessary so the water level is even.)
 
First off i agree with everyone in that you should place the tank across at least two beams or add some extra support. If you have a finished basement this could be a pain because you'll have to rip out the ceiling, but if its the choice between having your house collapse and removing a 3x3 section of ceiling, i think the choice is clear.

Second, this is straying from the original topic, but how important is it that the tank is level? One end of my tank is about 3/4 of an inch to an inch lower than the other side. Luckily the overflow box is at the lower end.

Sorry to stray off topic, but this could be important.

-Dan
 
Here's a good article on structures and placment of tanks:
http://www.cichlid-forum.com/articles/aquarium_weight.php

how important is it that the tank is level
It was initially important in my case because of an overflow tube on each end - one side being higher than the other wasn't getting the overflow it should..

Somebody on this forum then mentioned that an uneven tank will put extra pressure on some seams, eventually "maybe a week, maybe months" causing the seam to rupture. I don't know if this is true or not, but I trusted his word and leveled the tank.. I went to Home Depot and bought some "composite shims" - they are basically wedges that are made of some composite, so they are strong.. One side of my tank - the water was 1/8" lower than the other, and I was able to hammer a shim under each side (front and back of the left side) of the (filled 125g tank).. The shims max at 1/4" height, and I had to put them all the way under- raising one side 1/4" to correct the 1/8" difference on the other end.. Yes I was able to raise the left side 1/4" even though we're looking at almost 1600lbs.. (the wedges and a hammer, good physics I guess..)

Your tank is off by 3/4" on one side?? is it the floor or the stand?? grab a level and find out.. if it's the floor, maybe a floor jack underneath could correct the house (are your nearby doors sticking??) otherwise, maybe get some strong folks to help lift it while you place something under one side..
 
Its definately the floor. If you put a ball or marle in the one corner it'll roll all the way to the other end of the room. Funny story actually because when we were setting up the tank (150g) it overflowed and we had some problems and the water made a dash for the electronics which, of course, are located at the lower end of the room. My roommate laid down on the ground to block the water, it was about all we could do.

Back to the present though, i will have to consider some shims. We can't afford to have this thing break. The tank is 3/4" tempered glass all around so it should stay pretty well, but why chance it.

So lets see, if your 125 gallon weighs 1600 pounds then i'm probably looking at somewhere around 2000 pounds.

The good news is pouring in today :D

-Dan
 
check here for approx. tank weight:
http://www.all-glass.com/services/techinfo.html

they say mine is ~1400lbs, but it depends on what you've put in it..

the water made a dash for the electronics which, of course, are located at the lower end of the rooom

That's another good point - while nobody ever wants to "plan for" a major tank disaster, if you have electronics in the same room (as many of us do I'm sure) - it's probably best keeping all the power strips up off the floor (just as you do, or should be doing with the power strips that run your tank).. the last thing you want is for water to short out all your computers and stereos etc.

as far as your floor - not sure if you own the house, but that kind of offset - you probably notice doors not closing right .. that kind of problem can be fixed (by a professional, not yourself ;-) where they jack up the problematic portion of the house to even things out..
 
Well no i don't own the place because i'm on the 11th floor of an apartment building...I think the whole place is off tilt, the leaning tower of boston i suppose. Although it does look straight from the outside :?

Hopefully we won't go through the floor!!! Or all 11 of them.

-Dan
 
that would suck.. in that case -get yourself some shims, but they are usually 1/4" high, might not be enough..
where in Boston? I lived in Davis Square for a while..
 
Having a level tank is very important. The only thing holding these tanks together are plastic top and bottom frames and a good beed of sylicon on all the seams. Water weights alot and if its un eaven more weight will be on one area of the tank. This is expecially important if the tank is not flat on the top of the stand. If the tank is flat on the stand but the stand is uneven on the floor then that will put more weight on one side of the tank.

Levling the tank now will save you from waking up or comming home to a massive amount of water on the floor.
 
You could put your tank in a place like a basement. I would suggest that if you have one because the floors should be concrete and be able to support a whole lot of weight, and there would normally be less sunlight in the basement so that means less algae.
 
I have a 65g tank (base is 36x18) and the weight is 800lbs. The tank sits on an outside wall and is perpinduclar to the floor joists. So I shuld be fine, right???
 
I am not an expert on construction, but i think that the weight is better distributed across the joists that with the joists. Or have i got it the wrong way round.

If you have a concrete base you have no worries, here in the UK i think it works out 10lbs per gal of water plus the weight of the tank/gravel/decor. If you are putting your tank onto joists i always feel it is better to be safe than sorry and but some extra supports in between the joist to make it stronger.

Like i said before i am crap at construction, but i know someone will tell me if i'm right or wrong.
 
You want the weight to distribute across as many joists as possible, therefore the tank should ideally be placed perpendicular to the way the joists run.

However, the joists have a definite load limit before they sag. The building code here says this is min of 40 lb/sq ft. If the tank has a foot print of 4'x2' & weight 1000 lb, it is exerting 125 lb/sq ft. Granted, the floor boards, etc, will spread the load over a larger area so the load will be smaller, but I would worry about the floor sagging. The floor prob won't collapse, but who want to deal with sagging floor, cracked ceiling, etc? Better to reinforce the floor, or put the tank right on top of a load bearing wall.

Or maybe ask a structural engineer friend to look ...
 
Back
Top Bottom