How many gl does my tank hold?

[texasranchers]

We bought a 35 gl hex tall Oceanic, 2 years ago from lfs.
This weekend we threw out the tap water and put in RO. Unless I miscounted the number of 5 gl bottles we put in, we don't have a 35 gl tank.

Exterior measurements are:
From straight outside trim to straight outside trim it measures, 18"
From pointed trim to pointed trim it measures 20 3/4"
From top of trim to bottom of trim it measures 25 1/4"

This is a 6 sided(hex) tank. Will someone help me calculate this?

[texasranchers]

Exterior measurements are:
From straight outside trim to straight outside trim it measures, 18"
From pointed trim to pointed trim it measures 20 3/4"
From top of trim to bottom of trim it measures 25 1/4"

This is a 6 sided(hex) tank. Will someone help me calculate this?



Height is 25 1/4" Oh BTW each panel is 10" wide

[::pete::]

21.6gal ....

[texasranchers]

No way! I wondered why it was so hard to keep tabs on the maintenance. I did use any tools, devices for measuring but I also kept it in my mind that I was told a 35 hex. Umm, do you think I can go back and get some more tank to make up the difference for what we paid??

[::pete::]

Height is 25 1/4" Oh BTW each panel is 10" wide

If each panel is 10" wide straighten the angles (you are not changing the volume just the shape) and you end up with 10" x 20" x 25".

[Instar]

Outside dimensions don't mean a thing. The water volume is based on inside dimensions. Total displacement of the tank, frame with the glass (glass thickness) is what you figure with outside dimensions. And frame measures will give a finished total of more than the actual displacement as they are larger than the tank. Then what is the contained volume of a 5 gallong jug? You have to measure it with something if you really want to know. To calculate the contained water volume for the tank, it takes inside dimensions and then you have to subtract for the silicone overrun in the corners and how far from the top you keep it to know how much water you have in there.

[::pete::]

I think he was looking for an idea and all the calculators from various sites ask for ?
L x W x H.

[JimD]

Each pane is 10" wide, 25.25" tall, whats the distance between the front and back in the center of the tank,, with that information I can get you in the ballpark. You have to calculate two seperate boxes and add them together... Should be simple givin the fact all panes are 10" wide. If the measurement in question is 18", I calculate the tank to be 39.34 US gallons approximately based on exterior dimentions.

[texasranchers]

All the deminsions that I have, have been given.
Exterior measurements are:
From straight outside trim to straight outside trim it measures, 18"
From pointed trim to pointed trim it measures 20 3/4"
From top of trim to bottom of trim it measures 25 1/4"

Height is 25 1/4" Oh BTW each panel is 10" wide

I cane up with 23.67gl. from a chart that I found.

[JimD]

That charts not right. Think about what Im saying, if all sides are equal, take the center square, and use the l x w x h formula, put the outer two angles together to form another equal square, do the same math and add them together. Difficult to get the concept accross without images. 25.25h x 10w x 18deep (front to back) = 4,545 x 2 = 9,090 divided by 231 = 39.34... Im pretty sure this is correct, Although Ive slept sice high school... lol

[::pete::]

I see how Jim got his and its definitely closer than my guess.

[NaCl_H2O]

Regular Hexagon Volume = H*(sqrt(3)/2 * W*W)
W = Distance front to back between flat edges
H = Height

Here is a link
(http://www.drking.plus.com/hexagons/misc/area.html)

Not taking into account glass thickness I get 30.67 gallons

[SaltyJim]

Grom what I remember, Oceanic made 2 smaller (<50gal) hex tank sizes. 42gal is the larger, and the one you have desctribed is the 30gal. If it truly is Oceanis, then with those dimensions, it is definitely 30gal.

Jim

[Ram_Puppy]

sounds just like my tank, not sure, I think it's a 30... it's been 'fun' keeping it stable.

[Richard]

No way! I wondered why it was so hard to keep tabs on the maintenance. I did use any tools, devices for measuring but I also kept it in my mind that I was told a 35 hex. Umm, do you think I can go back and get some more tank to make up the difference for what we paid??


A very common error is thinking that a 55 gallon holds 55 gallons or a 20 gallon holds 20 gallons and so on. Manufacturers base the tank size on outside dimensions rather than inside dimensions. As others have said, you have to use inside dimensions to figure out how many gallons they actually hold.

Bummer...I just figured out that my 215 only holds about 190 gallons which means I still have never owned a tank over 200 gallons. :x

[Richard]

Here's a calculator for Hex tanks:
http://animal-world.com/encyclo/information/calculate.htm

It says 32.79 gallons based on 6 sides 10" wide and 25.25" tall.

[texasranchers]

Thanks everyone for the replies.

I understand about the interior/exterior deminsions, I didn't need exact. I was just amazed that after hand filling my tank with the RO water from the supplier, that I had 10 gl left over.

Yes, it really is an Oceanic, I left the little sticky on the bottom trim.

This has been very beneficial. Thanks again and I'll check out the links.