have you ever considered the weight distribution of your tanks???

[Magnum Man58 173]

so, water is heavy, really the only things we add that weigh more is typically the substrate, and any large rocks, etc. I don’t think most prebuilt stands are fully supported, most span some sort of upright support, with a horizontal board, not as fully supported as the ends… as I build my stone pile, in the tank I’m trying to grow aufwuchs in, I’m lucky, as I noticed this morning, that I’m building the rock pile over my vertical support, in this case, it’s 75-80 pounds of 2-4 inch rocks, this in a standard 48 inch long 55 gallon tank… my stand is home built and used concrete block, as my vertical support, but I’m guessing using the cheesy particle board factory stands, building a heavy rock pile in the center of the tank could approach over stressing the cheap stands and even cause the tank to leak prematurely … anyone ever overload their tanks before???

 

[GaryE18 16]

Yup.

I responded to a leaking tank thread yesterday. I caused a leak by not taking floor unevenness into account, and not properly shoring up a rack. It held four 40 gallons, so a considerable weight, and the uneven floor (very minor at 1/8 of an inch) put intense pressure on one end strut. As it leaked very slowly in time from one seam, the wood began to soften, and the leak became noticeable. I fixed the silicone and built a new rack out of the wood from the old - a job I did not enjoy. I had to move 4 times 40.

But manufactured presswood racks should be Hallowe'en decorations to make you wake up screaming in the night!

I've never owned one that didn't eventually become a problem.

I have homemade 2x4 racks holding hundreds of gallons, and since I checked them all for evenness after that one mistake, I trust them absolutely. If I had a 20 gallon alone on presswood, I would worry about more than I do 16 20 gallons on a properly constructed 2x4 or strong, properly rated metal rack. And my carpentry skills approach those of your average windstorm.

 

[Magnum Man58 173]

my main tanks are built in, in the basement, on a concrete floor, using dimensional lumber most are 2X8’s and 10’s with a smaller “t” board on the edges of those to keep them rigid and straight across the middle, and concrete blocks as vertical supports those have been problem free ( knock on wood ) for 30-35 years… not all are perfectly level, as is the floor, but so far mine are problem free…

 

[Jennet37 95]

Having kept 2 x 4ft bow fronts in the 70's that had a metal stand with proper wood around the depth of 1.5 / 2 inches, I learned that all aquariums need a solid base. Which is why when I again had a Malawi aquarium in the 80's I placed it on a solid piece of furniture that had a top wooden depth of around 1.5 inches.

This is why my 80 litre is on a similarly built piece of furniture. If I get another larger aquarium to go on my other larger piece of furniture, there is an 'under cabinet' used initially for a small tortoise, that I will brace with 2x2 wood battens to ensure I don't get any bow in it. Hopefully, with the new aquarium placed on a yoga mat underneath, that should help deal with any potential problems. We can never say never, but we have to do the best we can for anything in our care.

 

[GaryE18 16]

I have been told but never confirmed, that a slightly uneven tank is fine as long as you never move it. Some will shift in their shape just a little (according to the theory) and if never moved will stay that way. But if you move them, they have different pressures and don't necessarily return to evenness.
It seems to make sense to me. If any engineers read this, please comment if you can.
Most of my aquariums have gone through one local house move and a second 900 km move to another province. That'll stress a tank...

 

[emeraldking37 88]

In general, houses overhere have ferroconcrete floors and walls. Non-load-bearing walls can also be made of aerated concrete, if desired.
A part of very old houses may have wooden floors in my country. In very modern houses, drywall is used when desired. But that's just a minority. In general, we only use drywall for ceilings.
Because concrete is mainly used in construction overhere, we can place a large fishtank without any problems. It will hold the weight.
Wood in construction is used as a threshold, overhang, window or door frame. But for most modern houses, the wooden window frames have been replaced with plastic ones. This goes also for doors on the outer walls of a house.

 

[Essjay57 172]

The 4 houses we have owned have had concrete ground floors. All were new builds, the first being 1979. Our elder son and his ex-wife had a floor made of wood slats with a cavity beneath - I found that house in the 1939 register but not the 1921 census so built between those two dates. It was so uneven I would not have risked an aquarium bigger than around 50 litres/10 gallons on that.

 

[Uberhoust6]

Definitely consider the weight distribution of the tanks. The first thing I look at is whether the fish tank has a floating bottom (IE the bottom is .5 to 1.0" above the bottom edge of the tank), this is the case with most of the recent tanks I have seen for sale in North America. If you have a floating bottom then only the outside edges of the tank needs support, this can affect the type of stand you use, I had a stand for my 70 gallon tank that was a welded stand with 4 legs supporting a rectangular frame of angle iron without any material or support in the middle. I also consider that these tanks cannot take as much of an internal load of substrate and rocks as do the tanks where the bottom of the tank also rests on the stand, so for these tanks you can make your stand as solid as you want but it won't help prevent the bottom of your tank falling out if it is overloaded. I also consider where the tank sits in the room. I like a main display tank in my upstairs den area, if I place the tank in an upstairs room, I will pull the house drawings and ensure I place the tank near a supporting wall and a location where the tank spans as many joists as possible.

A note on particle board stands. I used to build all my own stands but my latest is a MarineLand stand that came with my 75 gallon tank. I started with it and was going to build a new one but I made sure everything was level, put the tank on the particle board stand, and it has been there since. Overall, the particle board is working quite well, it has more than enough strength to support the tank, has no motion when I walk on the floor. The only thing I worry about with the particle board stand is getting the bottom edges wet, I do have to be careful when filling and maintaining the tank to avoid water on the floor around the base of the tank. I have spilt water at the base before but have always clean up that spill immediately. The system is slightly less than 10 years old and I haven't damaged the floors or the particle boards of the stand yet. Particle board is not the best material to build a fish tank stand with but if it is what you have, use it but just make sure you treat it right (Keep it dry, don't move it under load).

I do consider the weight of the hardscape as well. I don't know what the silicone sealant can support and I don't know what the glass can support so I tend to mix rock with wood to keep the weight down. I will also use inert extrusive volcanic rock instead of slate, granite, or other more dense rocks if I am going to build up a large display using rock. I tend to try and keep the weight of the hardscape as low as possible, I spilled 3 gallons of water on my den floor once and was surprised how long it took to clean up, I don't want to have a larger amount to clean up.

 

[GaryE18 16]

Actual houses are an issue. In my last 3 set ups I've had a concrete floor. Before that, I had a chain of old rickety houses that were severely limiting. I didn't even think about tanks upstairs.
@Back in the fold hates it when we call aquariums tanks, but one of my homes was built right after World War Two as a housing project for returning veterans. The builders used war surplus materials, and the main beams under the main floor were huge railway steel lengths. I guess once the bombers weren't hitting rail lines anymore, there was no need to rebuild them.
Nothing moved in that house.
But some of the others I lived in would make tanks rock and roll. I would lay down plywood under the stands to try to stabilize things, but those were the years when I didn't have many aquariums.

Our aquariums are heavy. My old Malawi tank, with its rockwork was a test for any wooden floor. I think I lived dangerously in those days.

 

[Tomsfish16 15]

My understanding is all weight goes to corners.
My 6 foot 180 has no support in the middle. Only on the ends.
One of my favorite videos about tempered glass.

 

[Uberhoust6]

My understanding is all weight goes to corners.

It does in this case but that adds tensional stress to the bottom of the front and back panels and some compressive strain to the top of the front/back panels. On a typical rimmed tank I would think that the bottom edge is meant to be supported. You can support the tank from the ends but that has got to add more shear and tensional forces to the connection between the bottom and the front and back plates, both will want to bow out from the center of the tank. If the glass and silicone are up to the task (over engineered) then it will work, but if there are any weaknesses in the glass or silicone you would be increasing the overall chance of a failure. Supporting all the bottom edges reduces the strains on the silicone between the bottom and front/back plates of glass, it supports the weight of the water not the tension from the tank trying to twist up at the ends.