how to figure out water volume on a hexagonal fish tank?
- Thread starter saltyESQ
- Start date
bromion
Active member
Guess no geometry in law school? : )
I assume it's a perfect hexagon (all sides equal in size)? Easiest way is to get the area of the hexagon footprint:
48x48 - 4*1/2*16*16 = 1792 sq in
(that is the area of the 48x48 square minus the area of the four triangular corners that are cut out)
Multiply by the height
1792*36 = 64512 cu in
Which is 279.27 gallons
I assume it's a perfect hexagon (all sides equal in size)? Easiest way is to get the area of the hexagon footprint:
48x48 - 4*1/2*16*16 = 1792 sq in
(that is the area of the 48x48 square minus the area of the four triangular corners that are cut out)
Multiply by the height
1792*36 = 64512 cu in
Which is 279.27 gallons
dacoolguychris
New member
geez that's a big tank... 4ft by 4ft by 3ft.. nice show tank somewhere..
SaltyESQ: you currently own it or thinking about getting it?
SaltyESQ: you currently own it or thinking about getting it?
Scissorhand
New member
*pfftt**
just use 5 gallon jugs as measurement and start counting up.
just use 5 gallon jugs as measurement and start counting up.
anthias_lover
New member
Just get a one gallon empty milk container, fill it with water, and keep dumping all the water into the tank. Count how many times this takes until the tank is full. That's how many gallons…j/k
bromion, your footprint calculation is not right. The volume of four triangular corners are not 4*16*16. 16 is the base, not the side length. The formula for the area of the hex base is (3/2)r^2*sqrt(3).
or A = (3/2)16^2*sqrt(3) = 665.1 in square
so V = 665.1 * 36 = 23943.9 in cube
Which is 103.65gal of water.
You can double check by typing the numbers in this link:
http://www.reefwaves.com/volume_calc.php
bromion, your footprint calculation is not right. The volume of four triangular corners are not 4*16*16. 16 is the base, not the side length. The formula for the area of the hex base is (3/2)r^2*sqrt(3).
or A = (3/2)16^2*sqrt(3) = 665.1 in square
so V = 665.1 * 36 = 23943.9 in cube
Which is 103.65gal of water.
You can double check by typing the numbers in this link:
http://www.reefwaves.com/volume_calc.php
and it would be 311
BurntOutReefer
New member
my head just imploded.....
3checkmark3 over 2, s2h,where s is length....
3checkmark3 over 2, s2h,where s is length....
Scissorhand
New member
Just think of the implications if calculations were off:
# of livestock could exceed the fish-per-gallon golden rule
incorrect amount of B-Ionic dosing will OD the tank
Floor will collapse due to excessive amount of weight
The Earth slowing down causing unsuspecting reefers to eject into the bottomless pits of space!
# of livestock could exceed the fish-per-gallon golden rule
incorrect amount of B-Ionic dosing will OD the tank
Floor will collapse due to excessive amount of weight
The Earth slowing down causing unsuspecting reefers to eject into the bottomless pits of space!
Here's another volume calculator done by jdieck. He's the same one that did the Reef Chemistry Calculator which is the second link 
http://reef.diesyst.com/volcalc/volcalc.html
http://reef.diesyst.com/chemcalc/chem_calc3.html
http://reef.diesyst.com/volcalc/volcalc.html
http://reef.diesyst.com/chemcalc/chem_calc3.html
anthias_lover
New member
Bigmike, can you explain how he has a correct calculation about his hex area? and how you came up with 27.7 inches?
The way I see in his calculation is incorrect. If he has the area of the four triangular corners, according to his calculated 4*1/2*16*16, that means the other four lengths must be 48 - (2x16) = 16 in. But it is incorrect in hex case. You can draw a pic and see what I mean.
My result was base on 16 in of size length, to response to bromion's result. The original question/given is not clear about the lengths. My given formula to calculate the hexagon area (3/2)r^2*sqrt(3) is correct.
There are many ways to calculate the hex area, but most people don’t care about how volume calculator comes from on web. They just type numbers in and have an answer…avoid the headache I guess.
dacoolguychris
New member
and stioll i ask.. PICS!!!!
dacoolguychris
New member
and still i ask.. PICS!!!!
bromion
Active member
Bigmike's is right if it's 48" from flat side to flat side. 311 g
You can find the length of a side in that case by trigonometry:
side length = (48/2)/sin(60deg) = 27.71" (about)
Of course, it could be 48" from point to point. In that case, the length of a side is 24", meaning the volume is 233.4 gallons
You can find the length of a side in that case by trigonometry:
side length = (48/2)/sin(60deg) = 27.71" (about)
Of course, it could be 48" from point to point. In that case, the length of a side is 24", meaning the volume is 233.4 gallons
dacoolguychris
New member
i know math would help one day.. yeay law of sines... either way.. it's a big tank..
saltyESQ
New member
Not to make things more complicated, but I finally got the tank and here are the exact measurements. It's a perfect hexagon, diameter is 42" (measuring from the 2 opposite flat sides) and 48" (measuring from longest points of the hexagon), 29.5" tall, and each of the flat hex sides are 24" across (from edge to edge of the hexagon). Can someone recalculate the tank volume for us liberal arts majors? The guy who sold it to me said it was a 200g. I think he's close, but I'd like to know for sure so I can buy the right skimmer. Here's some pics for those who need to visualize. It's still pretty dirty, but you get the idea.
I have another question: how big should the holes be for the overflow and return? They seem a little small to me. Take a look at the pic of the inside overflow and let me know what you think.
Thanks much.
I have another question: how big should the holes be for the overflow and return? They seem a little small to me. Take a look at the pic of the inside overflow and let me know what you think.
Thanks much.
anthias_lover
New member
Are you kidding me? all the numbers above are given. It's about 191 gal. Try to figure it out bud...
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