Let me start by saying that I am by no means an expert in aquaria, engineering, physics or hydrostatics.
Recently (July 2015) I set up a new tank, an ADA 75P, which is 75cm length, 45cm width and 45cm depth
(or 2 & 1/2 foot long, 1 & 1/2 foot depth and 1 & 1/2 foot height).
It can take up to 151.875 litres or 33.4 US gallons, thus the water weighs 152 Kgs.
I have had it running since July, but only just recently I noticed that it is slightly tilted.
Me worrying is probably unrealistic and I am just being paranoid.
I tend to be paranoid about my tank, because of all the horror stories I've read online.
In order to avoid perpetuating the myths about unleveled tanks, I've done some proper calculations, in order to demonstrate my train of thoughts.
I've calculated the tilt, by finding the height from the water surface to the glass edges in all four corners.
The amounts are minuscule:
I worked out the angular change in degrees:
We need the average Kgf/cm2 in order to calculate the force for the entire side pangels, thus 1.02232 Kgf/cm2 halfway from the top to the bottom of the tank.
My side glass panels are 45cm * 45cm = 2025 cm2, thus I get 2070 Kgf per side panel,
and my front and rear panels are 75cm * 45cm = 3375cm2, thus I get 3450Kgf per front/rear panel.
All panels are 8mm thick, optiwhite (low iron glass) with the only exception of the bottom panel which has higher iron (green tint).
I did those calculations, to show just how strong those glass sides are supposed to be, in order to handle the forces exerted on them by the water.
However, because I am paranoid, I figured out the way to calculate extra force:
by finding the Sine of the angle, as it is proportional to the pressure exerted by the water
Thus, in my case:
(I just read a lot of online resources to figure this out)
The numbers are also a bit inflated: out of 152 litres, I will probably stop at 140 litres, thus the actual force is probably a bit smaller.
Also the angles may be smaller, since I cannot accurately measure (using a measuring tape) from water surface, that is quite hard to do.
What those calculations show, is that even minute changes have a big effect, 15 kgf increase on the side panels due to tilt,
9.2 Kgf increase on front panel due to tilt, and 25 Kgf increase on front panel and right side panel due to the front right corner being lower than all other corners.
However, in the grand scheme of things, those silicone seams are made to withstand at least 3450 Kgf at their lowest level (or else they would break when you overfill the tank).
Will a 0.27%, 0.46% or 0.74% increase in the force due to tilt have such a significant effect?
I am guessing that I have no reason to worry, but after googling "aquarium tilted" or "fish tank tilted" I run into a plethora of guides and posts,
ranging from the downright fanatics arguing that they need to be perfectly level or the tank/seams will break,
or reading articles from "experienced aquarists" who have kept all their tanks unleveled and never had any issues.
Some argue that anything smaller than 1/4 of an inch is no reason to worry,
whereas others mention that aquarium quality, braces or seam silicone, previous usage, all affect aquarium safety and longevity.
So, from your experience, assuming you've actually given this any thought or attention, how level have you kept your tanks?
Obviously tank capacity is probably the crucial factor here, but I'd like to know if I should be emptying my tank and buying shims,
or if this is one of those urban myths propagated through online forums.
PS: If you are an engineer or are experienced with hydrostatics and such calculations, I'd be more than happy to be given some input on the above calculations
)
Recently (July 2015) I set up a new tank, an ADA 75P, which is 75cm length, 45cm width and 45cm depth
(or 2 & 1/2 foot long, 1 & 1/2 foot depth and 1 & 1/2 foot height).
It can take up to 151.875 litres or 33.4 US gallons, thus the water weighs 152 Kgs.
I have had it running since July, but only just recently I noticed that it is slightly tilted.
Me worrying is probably unrealistic and I am just being paranoid.
I tend to be paranoid about my tank, because of all the horror stories I've read online.
In order to avoid perpetuating the myths about unleveled tanks, I've done some proper calculations, in order to demonstrate my train of thoughts.
I've calculated the tilt, by finding the height from the water surface to the glass edges in all four corners.
The amounts are minuscule:
- From rear left back corner to front left corner the difference is 2mm ( 0.008 of an inch)
- From left front corner to right front corner the difference is 2 mm (0.008 of an inch)
- From rear left back corner to rear right corner the difference is 2mm
- From rear right back corner to front right cornet the difference is 2mm
I worked out the angular change in degrees:
- 0.25465 degrees: rear left back to front left corner
- 0.15279 degrees: front left to front right corner
- 0.25465 degrees: rear right back to front right corner
- 0.15279 degrees: rear left to rear right corner
- 0.26192 degrees tilt
We need the average Kgf/cm2 in order to calculate the force for the entire side pangels, thus 1.02232 Kgf/cm2 halfway from the top to the bottom of the tank.
My side glass panels are 45cm * 45cm = 2025 cm2, thus I get 2070 Kgf per side panel,
and my front and rear panels are 75cm * 45cm = 3375cm2, thus I get 3450Kgf per front/rear panel.
All panels are 8mm thick, optiwhite (low iron glass) with the only exception of the bottom panel which has higher iron (green tint).
I did those calculations, to show just how strong those glass sides are supposed to be, in order to handle the forces exerted on them by the water.
However, because I am paranoid, I figured out the way to calculate extra force:
by finding the Sine of the angle, as it is proportional to the pressure exerted by the water
Thus, in my case:
- Sine( 0.25465 degrees ) = 0.00444447 * 2070 Kgf = 15.33 Kgf increase (0.74%)
- Sine( 0.15279 degrees ) = 0.00266669 * 3450 Kgf = 9.2 Kgf increase (0.27%)
- Sine( 0.26192 degrees ) = 0.00457135 * 2070 + 3450 Kgf = 25.2 Kgf increase (0.46%)
(I just read a lot of online resources to figure this out)
The numbers are also a bit inflated: out of 152 litres, I will probably stop at 140 litres, thus the actual force is probably a bit smaller.
Also the angles may be smaller, since I cannot accurately measure (using a measuring tape) from water surface, that is quite hard to do.
What those calculations show, is that even minute changes have a big effect, 15 kgf increase on the side panels due to tilt,
9.2 Kgf increase on front panel due to tilt, and 25 Kgf increase on front panel and right side panel due to the front right corner being lower than all other corners.
However, in the grand scheme of things, those silicone seams are made to withstand at least 3450 Kgf at their lowest level (or else they would break when you overfill the tank).
Will a 0.27%, 0.46% or 0.74% increase in the force due to tilt have such a significant effect?
I am guessing that I have no reason to worry, but after googling "aquarium tilted" or "fish tank tilted" I run into a plethora of guides and posts,
ranging from the downright fanatics arguing that they need to be perfectly level or the tank/seams will break,
or reading articles from "experienced aquarists" who have kept all their tanks unleveled and never had any issues.
Some argue that anything smaller than 1/4 of an inch is no reason to worry,
whereas others mention that aquarium quality, braces or seam silicone, previous usage, all affect aquarium safety and longevity.
So, from your experience, assuming you've actually given this any thought or attention, how level have you kept your tanks?
Obviously tank capacity is probably the crucial factor here, but I'd like to know if I should be emptying my tank and buying shims,
or if this is one of those urban myths propagated through online forums.
PS: If you are an engineer or are experienced with hydrostatics and such calculations, I'd be more than happy to be given some input on the above calculations
