Aquarium Weight

Freshcatch

At what tank size should you be concerned with the weight of the setup on the floors? It seems that some floors are not constructed as well as they once were. You have composite beams under the floors, when in the past you had a large 2x8 or 2x10 supports under floors. I know that one LFS, that is now defunct in our area, went out and installed additional supports under the floors during some installs.

JDM

If your floor bounces when you walk, any tank weight will be an issue but not breaking the floor issues, it wobbles and creates waves (dynamic non-vertical loads) which, if wobbling enough, could lead to an issue with tipping. Tanks on stands are top heavy.

In that case, putting the tank against the outside wall puts it as close to large support as possible and even then the inside edge of the tank could be on springy floor joists or, if it has feet, the feet could be between floor joists which is even springier, it's only a plywood span at that point in anything less than 40 years old... Maybe now it's 50 years.

I'd say that anything bigger than a 15 gallon needs attention to this, perhaps not more support, but checking what is there.

More support is likely worth considering at 40 gallons and up.

Almost forgot, attaching the stand to the wall is worth the effort BUT the tank stilll needs to be stable first.

Jeff.

Absntmind

Freshwater weighs about 8.33 lbs per gallon, saltwater closer to 8.5 lbs per gallon. Then you need to account for weight of stand, aquarium, substrate, rocks, etc.

A standard 55 gallon glass aquarium will weigh about 625 lbs filled. Now if you have a sand substrate a few inches deep add another 126 pounds (wet sand). Once you add a stand, pumps, rocks, lights, canopy, a 55 gallon tank can weigh anywhere from 800 lbs - 1,000 lbs (½ ton).

I would be careful on tank placement in a pier and beam house. You might cause the floor to bow, which in itself could cause a host of issues. I do know people who have large tanks in a pier and beam house without a problem to date. IMHO, it depends on the house as some are built much better than others.
We are currently renting an older home and I will only keep our 55 gallon in room which was an addition with a concrete foundation. This is because the floor doesn't feel solid enough for me to take the risk.

I know much of this was a non answer, lol, just thought I would put it out there.

Freshcatch

Each install would be on a case by case basis. Some homes would not be able to support the kind of weight when loaded with displays above 55-75 gallons. In posting the original thread, most of it was out of curiosity, but I have never heard of a floor giving way due to the weight of an aquarium.