Bubble_B0y
Aquarium Advice Addict
I have an octagon tank - 8 sides
does anyone have a formula to calculate the number of gallons for this tank
does anyone have a formula to calculate the number of gallons for this tank
need formula to calculate gallons in a 0ctagon tank - thanks
- Thread starter Bubble_B0y
- Start date
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QTOFFER
Aquarium Advice Addict
Google rocks!
Determine the area of the octagon in square inches or centimeters...
http://microgeometry.netfirms.com/content/octagon.html
Multiply by the height in inches or centimeters
Go here to convert cubic inches to gallons
http://www.onlineconversion.com/
or
1000 cubic centimeters (cc) = 1 liter. That's why I prefer metric volume calculations.
Determine the area of the octagon in square inches or centimeters...
http://microgeometry.netfirms.com/content/octagon.html
Multiply by the height in inches or centimeters
Go here to convert cubic inches to gallons
http://www.onlineconversion.com/
or
1000 cubic centimeters (cc) = 1 liter. That's why I prefer metric volume calculations.
Bubble_B0y
Aquarium Advice Addict
thank-you !!
i found another way - it works too
pretend your tank is a cylinder
i used cylinder volume to calculate.
pi x (rxr) x h
pi=approx 3.14
r= distance between facing sides
h=height
i found another way - it works too
pretend your tank is a cylinder
i used cylinder volume to calculate.
pi x (rxr) x h
pi=approx 3.14
r= distance between facing sides
h=height
Bubble_B0y
Aquarium Advice Addict
i caculated my tank - 10 gallons
what's the best filter i should get for this tank ??
any ideas
i was thinking an aquaclear MINI ???
what's the best filter i should get for this tank ??
any ideas
i was thinking an aquaclear MINI ???
greenmaji
Aquarium Advice Addict
how wide are the panels of the tank? I would try to find out how wide the mini is.. HTH
Bubble_B0y
Aquarium Advice Addict
yepp the MINI fits perfectly -
from the HAGEN website -
aquaclear MINI dimensions - 5 inches wide
my 10 gallon octagon panels are 6 inches wide !!!!
perfect match !!
it says the aquaclear Mini filters 100gallons per hour
my tank is 10 gallons.
Would this be enough?
or should I get 2 aquaclear Mini's ??
from the HAGEN website -
aquaclear MINI dimensions - 5 inches wide
my 10 gallon octagon panels are 6 inches wide !!!!
perfect match !!
it says the aquaclear Mini filters 100gallons per hour
my tank is 10 gallons.
Would this be enough?
or should I get 2 aquaclear Mini's ??
greenmaji
Aquarium Advice Addict
1 is more then enough.. sounds like good luck! 
You said
typically r describes radius but what you have up there describes diameter.
also the formula there is the forumula for a circular aquarium also pi·r^2·h It will be very close, but I dont think it will be exact.
You can probly find a better forumula but I just drew this one up. You need to know:
x=length of one pannel of the aquarium
d=The distance from one flat side to another
Area = d^2 * 2((x+d)/2)^2
If you measure in inches, the answer is in cubic inches. To make cubic inches into gallons, divide by 231 for cubic cm into gallons, divide by 3 785.4
Hope this helps, if you cant do it yourself post the dimensions i'm sure someone will help ya.
If you just treat it like a circle, you will have a much more simple formula, but the result will be a bit off (but not too far)
typically r describes radius but what you have up there describes diameter.
also the formula there is the forumula for a circular aquarium also pi·r^2·h It will be very close, but I dont think it will be exact.
You can probly find a better forumula but I just drew this one up. You need to know:
x=length of one pannel of the aquarium
d=The distance from one flat side to another
Area = d^2 * 2((x+d)/2)^2
If you measure in inches, the answer is in cubic inches. To make cubic inches into gallons, divide by 231 for cubic cm into gallons, divide by 3 785.4
Hope this helps, if you cant do it yourself post the dimensions i'm sure someone will help ya.
If you just treat it like a circle, you will have a much more simple formula, but the result will be a bit off (but not too far)
fish_4_all
Aquarium Advice Addict
I don't know how to post it here but I have a excel sheet set up to do the calculating. If anyone wants it, send me an email or IM. If someone knows how to post a spreadsheet let me know.
I would try to explain it but I don't know for sure if I can explain it to myself.
If the staff has any ideas, I will send it to them so they can post the spreadsheet.
I would try to explain it but I don't know for sure if I can explain it to myself.
If the staff has any ideas, I will send it to them so they can post the spreadsheet.
fish_4_all
Aquarium Advice Addict
ok, here is the formula if someone wants to post it somewhere more useful.
In order to calculate it I took the triangle formed in each corner and moved them to other side to form 2 rectangle cubes.
Now you calculate the volume of the two cubes.
This calculation was done on an octagon that has 10 inch sides and 10 inches high.
A^2 + B^2 = C^2 Basic right angle triangle side calculation.
Take one side of the octagon and square it, divide it by 2 and then take the square root.
Example, 10 inch side: 10^2 = 100, divide by 2 = 50, square root equals 7.0711.
7.0711 is the length you need to add to the sides to calculate the volume of the octagon.
This number is added to once to one side and twice to the other.
Example: sides are now 17.0711x 24.1422 x 10; simply multiply all them together for the first volume. 4121.339 is the volume in cubic inches of the first cube.
For the second cube formed you multiply the side length by the calculated length.
Example: 17.0711 x 10 = 170.711
Add them together for a total of 4292.05
Now divide by 231 for the volume in gallons, which comes to 20 gallons.
In order to calculate it I took the triangle formed in each corner and moved them to other side to form 2 rectangle cubes.
Now you calculate the volume of the two cubes.
This calculation was done on an octagon that has 10 inch sides and 10 inches high.
A^2 + B^2 = C^2 Basic right angle triangle side calculation.
Take one side of the octagon and square it, divide it by 2 and then take the square root.
Example, 10 inch side: 10^2 = 100, divide by 2 = 50, square root equals 7.0711.
7.0711 is the length you need to add to the sides to calculate the volume of the octagon.
This number is added to once to one side and twice to the other.
Example: sides are now 17.0711x 24.1422 x 10; simply multiply all them together for the first volume. 4121.339 is the volume in cubic inches of the first cube.
For the second cube formed you multiply the side length by the calculated length.
Example: 17.0711 x 10 = 170.711
Add them together for a total of 4292.05
Now divide by 231 for the volume in gallons, which comes to 20 gallons.
fish_4_all
Aquarium Advice Addict
BTW, what is the length of one of your panels to see how accurate this actually this. 
DeFeKt
Aquarium Advice Addict
Or do
Overall width x Overall Length, meaning work it out as if it is a square
Then obviously the four triangles added together will make another square, so just take it away from the first digit then x by height of tank.
Example.
Overall width x Overall Length, meaning work it out as if it is a square
Then obviously the four triangles added together will make another square, so just take it away from the first digit then x by height of tank.
Example.
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