90 Gal + owners please read & respond


New member
I want to know what kind of joist work you have beneath your 90 gallon or larger aquarium. I have a full basement underneath where the tank will sit. It will sit on top of a 12' span supported by 2x10's on 16" centers. There is 3/4" subfloor, 3/4" T&G flooring on top of that and then glued pergo on top of that.
I'm trying to make sure that my reef doesn't end up in the basement.


New member
I am too going to test structural integrity of my 3rd floor apartment :)

The guy at LFS said that most apartments should be able to handle 90G tank (with LR, LS, etc...) So, I am going to test his theory pretty soon. wish me luck :D


New member
mine is in the basement on a concrete floor (well carpet and padding on that but still..)

it was fine in my old house, I had the usual flooring joists whatever the measurements are.


In Memoriam
You should be ok with the 2x10 joists,,,When I had my 90 upstairs, I have 2x8" joists --- 12' span... with 3/4" floor boards, and 5/8" subflooring... I was worried so I put a floor jack underneath in the basement... when I remodeled the basement, I had to take out the floorjack,, the joists never even settled... I was worried for nothing......


New member
your only talking like 1100 lbs with live rock and all.
i had mine on a 2nd floor of a apartment.
what your saying should be fine.
especially on 16inch centers.


On Yer left!
Premium Member
Mine is sitting against an outside wall the"wrong way". The tank is parallel to the floor joints instead of perpendicular. Since it is an 18" tank, it only sites on one 2"x10"x??' joist. Been a couple of years and it hasn't fallen through the floor yet.

itz frank

Gives Bad Advice.
90gal with 100lbs live rock, 80lbs livesand, 29gal sump, stand, canopy and lighting. Next to it is a computer desk full of books and tv on top of it. All on the second floor of our apartment building.


New member
just set the tank perpendicular to the floor joists, i mean it should be fine anyways but if you are worried and you can do it set the tank across the beams


New member
Well, I have a 110 gallon, a 90 gallon, and a 16 gallon all in the same part of the house, and we have braces under the 110 gallon, but no where else. it's been there about 8 years, and no problems with the floor. Sometimes I worry, but it should be just fine...