Hex Tank - Need to Determine Volume?

[JazzyB]

Hi peeps,

I just got a hex-tank from someone and was wondering if any of you knew how to determine the volume.

Here are the specs:

Height: 24 inches
Circumference: 10 inches per side x 6 sides = 60 inches
Distance straight across top of tank = 17.5 inches

If you can help let me know. Thanks in advance.

BTW: If you have any ideas for this tank give me a shout!


Jazzy:cool:

[Alastair]

The formula for multi-sided tanks (works for hexagons, octagons, whatever, so long as all sides are the same length) is:

((TOTAL PERIMETER INCHES x SINGLE SIDE INCHES)/2) x HEIGHT INCHES

This will give you volume in cubic inches, then just divide by 231 to get gallons.

[JazzyB]

So then according to you it works out to be something like this:

Total Perminter(60 inches) X Single Side (10 inches) /2 X height (24) = 7200

7200/ 231 = 31.16 Gallons

Hmmm... interesting. What I eventually did was to break down the hex into geometric shapes and did the math. I got approximately 27. Maybe I was wong. I haven't done this type of math in ages.

[caseyt]

using geometry, i came up with the following

what you've with a regular hexagon is one center rectangle with two triangles with 10" sides on either end of the rectangle.

to get the long leg of the rectangle and the hypotenuse of the triangle (they're the same), use the pythagorean theorem: a²+b²=c², or in this case 10²+10² = x². i came up with 14.142 for this side.

since you've got equal sides, you assume that the two triangles on the end when placed together are equal to the centar rectangle, so you can do your calculation by multiplying the center rectangle's area by two.

[2(10 x 14.142 x 24)]/231 = approx. 29.386 gallons

not sure if this applies to aquaria, but it was definitely worth five minutes of effort.

[Alastair]

Interesting that there should be a discrepancy, I'm not sure why that is (math is not my strong point). At any rate, the figures are pretty close, so the discrepancy is probaby academic for most purposes. Most tank sizes as reported by manufacturers are estimates, by my calculations they may be off by as much as 3 or 4 gallons in some cases. Case in point -- I once ordered breeder type tanks from two different manufacturers, both supposedly 30 gallon tanks. one was 30*18*12 (28 gal), the other was 36*18*12 (33.6 gal). Anyway, the point I'm going for is that approximate values seem to be commonly accepted. It's possible that that formula only gives an approximate value (don't remember immediately where I found it, had it written down in a notebook for ages). But I still don't know why the two of you using geometry would have got different answers.

[chefkeith]

casey- pythagorean theorem is for right angle triangles.

Hex area = 0.866 times the square of its smallest width
or
Hex area = 2.598 times the square of its side length

Given the dimentions that Jazzy gave us (which probably isn't exact) his tank is between 27 and 27.5 g's.

[JazzyB]

Hey guys!

Thanks for your help. I did measure the tank, however, with the casing, etc. the numbers are probably slightly off. I'm tending to agree with you that the tank is approximate 27 gallons. Thanks again.

Any suggestions on what type of fish would be suitable for this tank? A few people I know raise cichlids and were willing to give me a few juveniles. I was thinking that two at most with 3-4 juvenile silver dollars. It might get crowded quite soon. Let me know what you think.

[chefkeith]

I'd keep Lobsters in it, but thats just the chef in me.

[JazzyB]

Hahahahahahaha! That was hilarious. I had this picture of the tank with lobster instantly! And then taking them out for dinner. Cruel, but funny.

[Matt W]

I would advise against silver dollars, they prefer a bit of swimming room. In fact, I wouldn't put silver dollars in any less than 4 feet long.

As for cichlids, you might get away with some of the smaller varieties. Maybe a pair of kribs or rams? You could probably also do some shell dwellers in there...

[chefkeith]

I wasn't really joking about the lobsters. Hex tanks don't provide much surface area or room to swim around in and are hard to clean. Not a good tank for cichlids at all.

[Slappy*McFish]

You could have just filled the tank with water, 1 gallon at a time, to figure out the tank's capacity;)

[Firsttanks]

I found that Dwarf Puffers do well in a Hex tank, provided it is designed well, with tall plants and sightline obstructions the Dwarfs will occupy all levels of the tank.
When I was keeping my little guys in a Hex tank I had fake plants that were tall enough to reach from the bottom to the top, as well as floating plants. They had it sectioned off in 5 seperate territories Top left floating mass, top right, bottom right, bottom left and bottom centre (6 Dwarfs - 2 shared the bottom left territory)

[MrGoodbytes]

This may be a little late, but this is how I got the volume (see attached).
Gouramis would look nice in a tank like that, with some live plants, or maybe a pair of shell-dwellers.

Graeme

[JazzyB]

Wow! I'm impressed by the math skills. Good job. Hey Firsttanks what type of shelldwellers did you have in mind?

[MrGoodbytes]

Thanks :) (I had to use Photoshop to change the scan 'cause of my messy writing :p)
Did you mean firsttanks' suggestion about puffers, or mine about shelldwellers?
I'm really just going on book knowledge, but from what I've read shell-dwellers of the genus Neolamprologus stay small and eventually develop a little colony. Just be sure to give them a lot of big empty snail shells.

Graeme

[JazzyB]

shelldwellers?

[F.sparverius]

You might want to get a few corydoras. They love crusing up and down the sides of a tank and probably would not mind the tall sides.

[MrGoodbytes]

Sorry if I have been confusing you or anything like that. Shell-dwellers are little Cichlids from Lake Tanganyika that live in and around snail shells in the shallow water off-shore.
I thought they would make an interesting species tank if that's what you went for.
Again, sorry if I didn't answer your question the first time.

Graeme

[sumoschro]

if your tank really is about 30 gallons then a pair of angelfish would lok nice, plus they appreciate the extra vertical space.

[JazzyB]

Thanks to everyone for the math skills on determing the tank volume of 27 gallons.

Here's what I'm thinking of hosting in the tank. Let me know what you think both positive/negative.

1. 1 or 2 Blue-eye cichlids
2. 2 Dwarf Gouramis
3. 3-4 Pepper Corydoras
4. 1 Betta
5. Dwarf pleco (if there is one)

According to what I've read their parameters seem similar and it should make for a peaceful tank... I hope. My concern is with the blue-eyes because they are 4-5 inches. If you have any other suggestions fire away! I'm all ears... er... eyes.