55G tank 1/4" off level - Page 2 - GTA Aquaria Forum - Aquarium Fish & Plants serving the Greater Toronto Area.
GTA Aquaria Forum - Aquarium Fish & Plants serving the Greater Toronto Area.

Go Back   GTA Aquaria Forum - Aquarium Fish & Plants serving the Greater Toronto Area. > FRESHWATER > Equipment
Register FAQ Members List Calendar Advertise Search Today's Posts Mark Forums Read Advertise

Equipment Tanks, stands, heaters, filters, and all your favourite aquarium hardware in one place. Discuss.

Reply
 
Thread Tools Search this Thread Display Modes
Old 01-15-2009, 10:10 AM   #11
Riceburner
Want a pic?
 
Riceburner's Avatar
 
Join Date: Mar 2008
Location: The Hill
Posts: 2,606
Feedback Score: (44)
Riceburner is just really nice
Default

few months for mine...about late summer
Riceburner is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 01-15-2009, 11:37 AM   #12
Harry Muscle
Devoted Member
 
Harry Muscle's Avatar
 
Join Date: Mar 2007
Location: Hamilton
Posts: 1,046
Feedback Score: (29)
Harry Muscle is on a distinguished road
Default

Thanks for everyone's comments. There seems to be some conflicting ideas (ie: fix it vs. I left it and have no problems) on unlevel tanks, so I got thinking about the actual physics involved.

So I was wondering if there are any physics buffs out there that might help me figure something out ... does an unlevel tank (that is perfectly supported from below) actually encounter any extra stresses than a level tank. I know it's generally assumed that a tank that is not level has a greater chance of cracking, but is that really the case. It's obvious that a tank that's not supported well from below has a greater chance of cracking since the weight is not being distributed properly and that put's pressure points on the glass and/or seals. However, what if the tank is supported perfectly (ie: the surface it sits on is perfectly flat), but it's slightly unlevel. Does that in reality place any extra pressure on it? If it does, how much? Physics should be able to answer this for us.

I'm good with math and was good with physics years ago in school, but the problem I'm having is trying to figure out exactly what the logic is behind an "unlevel tank is more likely to crack". The best logic that I can come up with is that since the tank is unlevel that means that the glass panes are not vertical, so instead of just holding water in the tank (pressure along the x and y axis), there will also be a certain amount of water sitting on top of the glass (on the side of the tank that is lower) (pressure along the z axis). You might have to draw a picture to follow the previous explanation. But the amount of water is very small, for example, if a 4 foot tank (48" x 12" x 24" for example) is 1/4" unlevel from left to right, the glass panes on sides will be off from vertical by about 1/8". That means that that there will be about 18 cubic inches of water resting on the glass pane. That's 0.65 pounds of weight. I highly doubt that 0.65 pounds of water is able to increase the risk of a tank failing, or can it?

The 18 square inches of extra water adds 0.65 pounds of weight or pressure in the z direction. However, in the x direction, that same piece of glass (12" by 24" side) is already experiencing 114.37 pounds of pressure. So it's obvious that a slight unlevelness of the tank adds only a very small amount of pressure to one side. About 0.56%.

So far, what I'm seeing is that if the stand that the tank is on has any chance of warping due to being shimmed it might actually be better to leave a tank unlevel instead of risking an non flat surface developing for the tank to sit on. However, I am looking for more feedback and comments from others if possible.

So if anyone has any better ideas of why an unlevel tank is at a greater risk of failure let us know ... or maybe that's just a myth.

Thanks,
Harry
Harry Muscle is offline   Reply With Quote
Old 01-15-2009, 11:56 AM   #13
Riceburner
Want a pic?
 
Riceburner's Avatar
 
Join Date: Mar 2008
Location: The Hill
Posts: 2,606
Feedback Score: (44)
Riceburner is just really nice
Default

Well...

I don't think it's the glass that's at risk of cracking. It would be the seams. A 4' tank has the same glass on the sides, so the sides take less pressure? Maybe. Either way if the seams take the pressure of 4'xwhatever.... does being off vertical at the sides make them any less capable? I don't think so.
Riceburner is offline   Reply With Quote
 
Old 01-15-2009, 07:29 PM   #14
pat3612
Devoted Member
 
Join Date: Jan 2008
Posts: 2,344
Feedback Score: (10)
pat3612 is on a distinguished road
Default

Its been over a year now also it has 150 lbs of rock it.
pat3612 is offline   Reply With Quote
Old 01-16-2009, 12:05 PM   #15
PPulcher
Devoted Member
 
PPulcher's Avatar
 
Join Date: Nov 2006
Location: Richmond Hill
Posts: 305
Feedback Score: (1)
PPulcher will become famous soon enough
Default

Harry, if the stand is level and plumb, I don't see how it could be warped?
__________________
Cheers,

Andrew
PPulcher is offline   Reply With Quote
Old 01-16-2009, 12:21 PM   #16
Harry Muscle
Devoted Member
 
Harry Muscle's Avatar
 
Join Date: Mar 2007
Location: Hamilton
Posts: 1,046
Feedback Score: (29)
Harry Muscle is on a distinguished road
Default

Quote:
Originally Posted by PPulcher View Post
Harry, if the stand is level and plumb, I don't see how it could be warped?
I'm guessing you are referring to this part of my post:

Quote:
So far, what I'm seeing is that if the stand that the tank is on has any chance of warping due to being shimmed it might actually be better to leave a tank unlevel instead of risking an non flat surface developing for the tank to sit on.
It's true, if the stand is level and plumb it's not warped, but that doesn't mean it won't warp. Take for example a flat bottom stand that is designed to spread it's weight across the bottom evenly. If you shim one side you have now raised the stand and left gaps (ie: it's no longer flat bottomed). It might be level and plumb now, but the weight of the tank will now push on parts of the stand that were designed to transfer loads directly to the floor below and it will start to warp it. So in such cases in might actually be safer to leave the stand unlevel and not risk any warping. If on the other hand you have a stand that has legs, then it was designed to transfer it's weight only thru those legs and you can simply shim those. In that case it's better to shim. Hope that clarifies things a bit.

Harry

Last edited by Harry Muscle; 01-16-2009 at 12:24 PM..
Harry Muscle is offline   Reply With Quote
Old 01-16-2009, 03:43 PM   #17
PPulcher
Devoted Member
 
PPulcher's Avatar
 
Join Date: Nov 2006
Location: Richmond Hill
Posts: 305
Feedback Score: (1)
PPulcher will become famous soon enough
Default

I understand now. Thanks, Harry. I can't add anything more to the discussion I'm afraid.
__________________
Cheers,

Andrew
PPulcher is offline   Reply With Quote
Old 01-16-2009, 05:35 PM   #18
Riceburner
Want a pic?
 
Riceburner's Avatar
 
Join Date: Mar 2008
Location: The Hill
Posts: 2,606
Feedback Score: (44)
Riceburner is just really nice
Default

if you shim under the support verticals you are shimming the "legs". The flat bottom may warp or may not, but it won't matter, the supporting "legs" will be plumb. But like I said, I left mine.
Riceburner is offline   Reply With Quote
Old 01-17-2009, 11:12 AM   #19
wtac
Hunh?
 
Join Date: Mar 2006
Location: Somewhere between here and there
Posts: 2,464
Feedback Score: (5)
wtac has a brilliant future wtac has a brilliant future wtac has a brilliant future wtac has a brilliant future
Default

IMHO, if the plane is perfectly flat, the stress on the seams will hold fine. If there was any torque/twist, then one will have future issues and there will be stress points at the apex/valley. I've had my 35gal reef w/~ 1/2" off level (lower in front) for ~7years w/o issues.

To shim your pedistal style stand, as other poster has mentioned, add the shims to where the vertical supports are to properly support the weight of the aquarium.

HTH/JM2C/E
wtac is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 02:51 AM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.