[mrbelvedere]

So, this stand I bought it lopsided. This is one of the reasons why the ADA 60-P #2 tank is slightly bowing. I also think that part of my floor might not be 100% level.

The water level is a 1/2 inch lower on the back right side than the front left.

Naturally, this makes me VERY nervous. Sure, in reality, nothing will probably happen. It's a good quality tank, and we are only talking 18 gallons of water here. But with 50 shrimp, 12 nice dwarf cories, a $100 tank, a $50 light, and hardwood floors I have reason to worry. Murphy's Law.

Anyway, how do I go about shoring it up? My dad keeps talking about "shims". I'm not sure what exactly they are.

Anyone else with a similar experience want to provide some insight?

 

[Nightshop]

Shims. Little plastic doo-dads which come in thicknesses of: 1/16", 1/8", 1/4" and 1/2". They look like little horse-shoes.

 

[kkentert]

my 55 gallon FINALLY broke yesterday- not the whole tank, but the center support. I've know it was going to happen. It was on a stand I made for 2 years, and I had a solid top which I sanded a bit to aggresssively. The ONE corner of the tank was slightly off the stand, and I've noticed the sealant getting white over the past few month. Finally, the center support craked off from the pressure and now I have to go get a new tank & Stand tomorrow. it looks like I'm going to DOWNGRADE. :icon_frow I'm going to get a 46 gallon Oceanic Bowfront. I'm hoping that even though it's less gallons, I'll have more planting room because of the larger front to back area. We'll see. I know I'm going to kick myself for going down. I REALLY want the 72 gallon bowfront, but my Landlord and I are both afraid 700+lbs is a bit too much for the floor to handle. (It's in a wierd corner over a staircase where there are no walls/beams under it)
So yes-be concerned - then again, at 18 gallons, it's doubtful anything will happen for a good long while - but I'd shim it...

 

[PDX-PLT]

my Landlord and I are both afraid 700+lbs is a bit too much for the floor to handle. (It's in a wierd corner over a staircase where there are no walls/beams under it)

So if you had 4 big friends all stand in that corner at the same time, do you think something bad would happen?

 

[distrbd]

Mr.Belvedere,I think you should not wait too long .
Just try to find small pieces of 1/8" ,or 1/16" mild steel from any metal manufacturing place and put them under the legs of your stand and level it before its too late.

 

[bcreque]

Wow, is this a major concern if it is not 100% level? I've got a 55 that I just set up, nothing it it yet but water and a piece of driftwood (still waiting on some parts)...

 

[mrbelvedere]

Okay, I'll go to the hardware store today and see what they have.

 

[JHipkin]

When you get to the hardware store buy a 24 inch spirit level. It will help you get the stand level without the guess work.

 

[kkentert]

So if you had 4 big friends all stand in that corner at the same time, do you think something bad would happen?

If they stood there for 3 years something bad may happen. There is no bearing wall under this area of the house. It's kind of "free floating"- not really, but there is no support UNDER it, just the beams, which I'm not confident are good for folding 700+lbs for a few years straight. The home is over 100 years old, and I have no idea how sound it is - So I'm not going to chance it. *(even though I REALLY want that 72 gallon bowfront!)

 

[bcreque]

Personally, I think we often overestimate what is needed to support our aquariums' weight... or underestimate the strength of our floor, house, etc.

 

[kkentert]

Personally, I think we often overestimate what is needed to support our aquariums' weight... or underestimate the strength of our floor, house, etc.

But the question is - Is it better to over estmate, or under-estimate and potentially cause damage. Sure-75 gallons is PROBABLY fine in most cases, but each person has to decide if they're willing to take a gamble on something that could possibly cause thousands of dollars worth of damage. That is my concern. I'm going to have a strictural engineer check out my place to see if it looks OK or not. (yes-I'm VERY anal...)

 

[bcreque]

I agree with you, and I'm definitely in the category of the people I'm talking about. Just stating an opinion that we are probably still being a bit 'overcareful'... which I agree is better.

 

[boink]

i thought buildings are built with a factor of safety of like 2-3 times...

 

[mrbelvedere]

But testing those safety boundaries isn't a good idea.

 

[confuted]

i thought buildings are built with a factor of safety of like 2-3 times...

Building codes change as well. 100 years ago, there weren't any, so homes were just built. Some floors might be able to support an elephant; others might spell disaster if a fat person walks too fast.

 

[spectre]

Wow, is this a major concern if it is not 100% level? I've got a 55 that I just set up, nothing it it yet but water and a piece of driftwood (still waiting on some parts)...

If its a glass aquarium, yes it's a very big deal. they are designed to be level when full of water. This keeps equal pressure on all the seams. The farther out of level you are, the more pressure one seam will receive(read= fail sooner).

When you do use a level to check the level, make sure you do front to back, side to side, and if possible, diagonally across the tank. Get it as close as you can to being perfect, and you should have no worries.

 

[bcreque]

I immediately fixed it yesterday after reading this thread. It may still be slightly off from front to back (maybe like 1/8 an inch) but that is about to be fixed as well at least to the point I can't notice it.

It has been set up for a few weeks filled with water, hopefully it takes quite some time for it to weaken considerably?

 

[Gatekeeper]

But testing those safety boundaries isn't a good idea.

ABSOLUTLY and 100% Correct.

As far as people standing in a corner, which was mentioned, although the loading may be the same, is a "temporary loading condition" or in the engineering world a "Live Load". This is an instantaneous loading condition that will not be sustained indefinetly. A "Dead Load" (in this case the fish tank), will provide a constant loading condition on all structural supports and members below. This causes undue stress over long duration.

Think of it simplistically. Take a rubber band and stretch it out as far is it goes, then let go. It goes right back to normal. Now do the same thing and hold it for a month. When you let go, the elasticity of the rubber band has decreased, and it will take considerable time for it to stabilize, but will never go back to "its original state". This is due to the long term stress associated with the loading. (This is very simplified BTW, so heed this with a grain of salt).

So, the LONG TERM affects of a dead load, far outway the short term affects of a Live Load. however, a Live Load can be just as catostrophic in the right conditions. Imagine you have the fish tank in the corner, then 4 of your friends come and look at the cool new fish you just got. Now you have an excessive dead load, being further influenced by 4 live loads.

It cracks me up that people overlook the loading conditions of a fish tank and have fallen to the belief that "if my stand can hold it, the floor can too." This is so far from the truth. It is highly unlikely that most floors can't withstand excessive dead loads, because of the "FACTORS OF SAFETY", but those safety factors are there for extreme conditions and are just that....FOR SAFETY, not to be utilized for everyday use. Good example...driving your car with the fuel light on for every tank of gas, just because you still have gas left. You can do it, but its only a matter of time before something goes wrong and you run out of gas.

i applaud you for doing your homework kkentert and deciding to "tank down". Its a tough thing to handle, but you will sleep better at night I am sure. You can always buy another tank later...just another excuse for MTS.


BTW...i have the 72 gal AGA bowfront...hehehe.

 

[Gatekeeper]

When shimming....one point to make

Do not just shim the corner thats out. you need to shim the entire stand to maximize contact area with the floor. if you just shim a corner, then you have "elevated the tank" from the adjoining support members. So you basiocally need to shim from the highest point to the lowest point until level. This will ensure that the contact of the bottom joint is level as well.

Think of a board on a floor. Raise up one side, now you only have two points of contact, where you raised it and the opposing side. in this instance, the weight of the tank is going to try and force the remaining portion (not shimmed), to the floor, thus bending the support, and consequently, the tank. All this stress will be on the joints.

you were out a 1/2" which means that considerable amount of shimming should take place. This is why its always good to do this before you fill the tank, making it alot easier.

Another point (while i am on a roll) is if you do shim before the tank is full, to check level after you fill the tank. The floor will deflect naturally to handle the weight. in most instances it will be neglibile or barely noticable, but its always good to check and make final adjustments if necessary.

My .02 rant is over with...i digress.:biggrin:

 

[PDX-PLT]

As far as people standing in a corner, which was mentioned, although the loading may be the same, is a "temporary loading condition" or in the engineering world a "Live Load". This is an instantaneous loading condition that will not be sustained indefinetly. A "Dead Load" (in this case the fish tank), will provide a constant loading condition on all structural supports and members below. This causes undue stress over long duration.

"dead load" is the defined as the weight of the structure. "live load" is the load that the structure supports. There is no requirement that a live load be short-term or instantaneous (although unlike dead loads, the live load can be dynamic and over the short term can be many times the weight of the object; e.g., a person jumping up and down). Things like furniture and storage items are considered live loads even though they are effectively permanent.

Long term live loads to not "causes undue stress" if the load does not exceed the yield point of the structures components (the point at which the components stops being elastic and permanently deforms). Unless one hears creeking, or other signs of deformation, it makes no difference whether those 4 friends are standing there for 3 minutes, or 3 years.

Think of it simplistically. Take a rubber band and stretch it out as far is it goes, then let go. It goes right back to normal. Now do the same thing and hold it for a month. When you let go, the elasticity of the rubber band has decreased, and it will take considerable time for it to stabilize, but will never go back to "its original state". This is due to the long term stress associated with the loading. (This is very simplified BTW, so heed this with a grain of salt).

This example is not applicable to building materials, but it does serve as a discussion point. In engineering terms, rubber is not an elastic material, despite the colloquial use of the term "elastic". As is pointed out here, rubber readily permanently deforms. In contrast, steel and dry wood return to there original shape when the load is removed, provided the application of the load does not exceed their yield point. As a corollary, such a load may be applied to the structure indefinitely.

Some times this is used on unusual structures to verify the capability to carry a load. Deflection is measured as a test load is increased, up to the tested-for amount. As long as the deflection is linearly increasing with the weight, the structure is still behaving elastically, and the yield point is not reached.

So, the LONG TERM affects of a dead load, far outway the short term affects of a Live Load. ...

How (from a physics and structural engineering POV)?

Imagine you have the fish tank in the corner, then 4 of your friends come and look at the cool new fish you just got. Now you have an excessive dead load, being further influenced by 4 live loads.

Good point; maybe I should have said 8 friends?

Perhaps my answer was a bit flippant, but the point I was making is that alot of times, IMHO, folks overestimate the "unusuallness" the the weight of a tank represents. A dinner party, a fully loaded wall full of floor-to-ceiling bookcases; etc., all can represent loading relatively equivalent to a mid-sized tank.