I was looking at the caresheets doing some research on some fish.

What's the difference between Tank Volume and Tank Size?

There seems to be some discrepancies.

I think you probably mean that volume as in litres, and the size as in length, width etc.

A tank could be say 100 litres, but really tall and not very wide for the fish to swim around. Or it could be 100 litres, but very long and not so tall etc. :)

Bit of a confusing reply, but I know what I mean!

Tank volume refers to the volume of water in litres. Tank size refers to the dimensions of the tank (length, depth, height). Volume is good for quick reference, but size is also important because you could have a tank that is e.g. [1000mm long x 500mm high x 400mm wide], when compared to a tank that is [450mm long, 450mm wide, and 1000mm high] (column tank). They would both be the about same volume - around 200 litres, but the second tank would severely restrict your stocking plan. That's why it's important to include both volume and tank size when posting stocking questions.

Tank volume (in milli-litres) can be calculated by multiplying the three dimensions in centi-metres. To get to cm from mm you simply take the decimal place back 1 space (so 1000.0 mm = 100.00 cm, or 10.00 mm = 1.00 cm)

For example:

100cm x 40cm x 50cm = 200,000 ml

There are 1000ml in a litre, so 200,000 ml is 200 litres.

Hope that makes sense, sorry that was the easiest way I could think of explaining it. Using deci-metres (dm) makes it a straightforward equation but a decimetre (10 cm) isn't commonly used.

EDIT: NAyfee beat me to it and explained it a lot simpler lol.

I thought so, it must be their bannerfish quantities are off.

Yeah, 379 litres is right (although not sure why it isn't rounded up to 400 litres) and the tank size should be something like 160cm x 50cm x 50cm I would have thought. Looking at all of the marine caresheets the tank sizes all seem to be in gallons rather than in feet or cm. Needs looking at I think.

Electrogear,
Why would the second tank size restrict the stocking options. I thought that volume of water was the key.

Is it due to restriction in swimming room?

Yes, like the column tanks I referred to, which are usually seen in hotel lobbies or restaurants, but I have seen a couple of them used in people's living rooms. Fish swim left and right more than they swim up and down, so horizontal space is much more important. A column tank would restrict you with numbers, but more imprtantly what type of fish you could keep. For example, a tang wouldn't have anywhere near enough swimming space in a 0.6m w x 0.6m l x 2m height tank, but if you turned the tank on its side it would be plenty.

That is one of the concerns I had when buying my tl-550 orca tank. Although it is 128 litres it is quite a tall tank and limits the fish type.