confusion about tank volumn

[treesprite]

I was under the impression that the hex tanks I have are 52 gallon tanks, but I have now looked at a few different lists, calculators, and forumlas which all give me different numbers. I am wondering if anyone actually has or had a tank of this description to give me a definitive answer without resorting to these online things.

 

The tank has 6 equal sides. It is about 25-3/8" high. From the center of one panel to the center of the one directly across (regardless of "side") there is about 22" which gives the impression that the tank would be similar to 22x22x25, except the angles take up volumn space. From corner to opposite corner is roughly 23".

 

Anyone know what the volumn is by experience rather than some online thing with potentialy faulty information?

[Jon Lazar]

treesprite,

 

I calculate just under 83 gallons when filled to the top, assuming that your measurements are all taken from inside the tank. I segmented the footprint into 12 equal right triangles and solved for the area of one of them...got 62.5 square inches. Mutiply by 12 to get the total area. Multiply by tank height to get the volume in cubic inches. Divide by the coversion factor of 231 for cubic inches per gallon. Answer is ~82.7 gallons.

 

Here's how to perform an empirical check. Pour 3 gallons and 1 quart of tap water into the tank. The water level should rise one inch from the bottom glass.

 

For all the junior members, this is why you have to do those story problems.

 

Jon

[dshnarw]

treesprite,

 

I calculate just under 83 gallons when filled to the top, assuming that your measurements are all taken from inside the tank. I segmented the footprint into 12 equal right triangles and solved for the area of one of them...got 62.5 square inches. Mutiply by 12 to get the total area. Multiply by tank height to get the volume in cubic inches. Divide by the coversion factor of 231 for cubic inches per gallon. Answer is ~82.7 gallons.

 

Here's how to perform an empirical check. Pour 3 gallons and 1 quart of tap water into the tank. The water level should rise one inch from the bottom glass.

 

For all the junior members, this is why you have to do those story problems.

 

Jon

 

 

Jon, I think you may have forgotten to divide by 2 when solving for the area of the right triangles.

 

I calculated 43 gallons. Test by measuring the length of one of those side panels. Should be about 12 5/8 inches.

[Jon Lazar]

Jon, I think you may have forgotten to divide by 2 when solving for the area of the right triangles.

 

I calculated 43 gallons. Test by measuring the length of one of those side panels. Should be about 12 5/8 inches.

 

Oops...I googled sin(30) and got 0.988. The actual retail value is 0.5.

 

Another reason why peer review is so important in reef aquaria!

[John]

Or the dumb way, fill the tank up gallon by gallon?

[Origami]

Yeah, I got 46 gallons.

 

12.7" on each panel and 22" panel-to-panel; 25.4" corner-to-corner; and 25.375 tall. (Note the difference between Forrest's corner-to-corner measurement - 23", which doesn't make much sense given her panel-to-panel measurement of 22 inches.)

[treesprite]

Yeah, I got 46 gallons.

 

12.7" on each panel and 22" panel-to-panel; 25.4" corner-to-corner; and 25.375 tall. (Note the difference between Forrest's corner-to-corner measurement - 23", which doesn't make much sense given her panel-to-panel measurement of 22 inches.)

The panels are 12" across. It was hard trying to measure the corner points because I had to hold a yardstick above the light fixture reaching around stuff to see numbers.

 

I have seen everything from 35 to 70 gal over about 6 or 7 websites. The most believable to me is the 40-ish to 50-ish range. I was thinking about selling one but can't very well do it if I don't know the size.

[Boret]

Hex tank volume calculator

 

43 gal seems the right answer.

[Origami]

The panels are 12" across. It was hard trying to measure the corner points because I had to hold a yardstick above the light fixture reaching around stuff to see numbers.

 

I have seen everything from 35 to 70 gal over about 6 or 7 websites. The most believable to me is the 40-ish to 50-ish range. I was thinking about selling one but can't very well do it if I don't know the size.

 

I'd say, then, that you're in the 40 to 45 range. If it's a true hexagon, then it's an easy enough calculation:

 

(2.598 * Panel width * Panel width) * (height) / 231 = # gallons

 

Use the inside dimensions so you can get the volume of the inside and you're golden.

 

For

Panel width = 12"

height = 25.375"

 

# gallons = (2.598 * 12 * 12) * (25.375) / 231 = 41 gallons

 

 

(I'm relying on the old HS geometry knowledge of a 30-60-90 triangle wherein the short leg of the triangle is one-half the length of the hypoteneuse (which is your panel width) and the the long leg is the square root of three times the length of the short leg. Given that your panel is reported to be 12 inches wide, the distance between panels would have to be 2*6*1.732 = 20.78 inches.)

 

Of course, if your panel measurement is a bit off, then so's the result. Plug in the right numbers and it'll work.

Edited August 14, 2009 by Origami2547