How to tell an aquarium tank volume?

[Temp]

Looking around, I see a lot of these phrases: XX-gallon tank

Let's say there's a tank with an unknown tank size. In my country, we don't use gallons to measure a volume of water. Instead we use liters. I know there's an online converter, so this doesn't worry me.

Should I fill the tank to the rim and count how many liters I had used to fill them up, as a way to measure the volume?

Or should I have to fill the tank up to 1 inch (2.5 cm) below the rim and measure the volume from there?

Thanks in advance.

 

[SeverumGuy]

If you don't want to try the online conversions, you can take the time to calculate the liters as your ad them to the tank. If you have a big tank then you'll be at it a while. Fill to the rim to know the full capacity, but once you ad all your substrate and decor then you won't have as much water in there anyway

 

[SeverumGuy]

What are the dimensions of the tank?

 

[neilanh]

There are online converters that will allow you to input the dimensions of the tank (Length, width and height) and it can calculate the volume of the tank for you - not just convert from liters to gallons.

 

[SeverumGuy]

There are online converters that will allow you to input the dimensions of the tank (Length, width and height) and it can calculate the volume of the tank for you - not just convert from liters to gallons.

Just gotta be careful which site you choose. I had two that told me my 55g was 55g and another that told me it was 58g. As much as I would like to have three more gallons, it's not quite there.

 

[Temp]

What are the dimensions of the tank?

What if it's not entirely cuboid? One side of the tank is round, while others are flat.

The height is 19 cm.

 

[thincat]

try here:Calculating Aquarium Volume - The First Tank Guide - How Can I Figure Out How Much Water My Fish Tank Holds?

 

[Temp]

Thanks, thincat. All of my tank are 1-gallon tanks, according to the converter.

But what if the tank shape isn't something that has width, height, and depth? like a vase, or a letter D shaped tank?

 

[thincat]

Good Question. I think I will ask "Google" that question. lol
Well I tried Google but the formula is above my Rating, so I guess the best way is the fill the contain with a known amount of liquid to find out the volume.

 

[jsoong]

There is a mathematical way to figure out the volume of any solid, but for complicated shapes, filling the tank with a pitcher of known volume might be easier.

For the OP's tank that has a D shaped base & straight sides, you can use the general formula of volume = surface area x water depth.

You measure the water depth from the bottom of the tank (or top of your substrate) to your intended water line.

For Surface area of the D shape, just think of the D as a rectangle plus a semicircle. Measure out the square/rectangular part and the surface area is length x width (easy!). If the front part of the D is a semi-circle, then the surface area is 1/2 * pi * (radius)squared.

The radius is half of the width of the tank.
pi is 3.14159....

If the D is an ellipse (ie a bow front) the surface area of the (half) ellipse area is:
1/2 * pi * semi-major axis * semi-minor axis
the semi-axis are like the radius, but because the ellipse is squashed, you measured 1/2 the longest axis & half the shortest axis.

This is a pic:
Area of an Ellipse -- Math Fun Facts

You add the area of the rectangle to the area of the semi-ellipse/semicircle & multiple that by your water depth to get the volume. If you measure in cm's, your result will be in mls.

PS - if all this is too much, just post a drawing with measurements & I'll figure it out for you!

 

[mgamer20o0]

my 2 cents is the difference between 50 or 55 isnt that much.... in a smaller tank you should be able to figure out even close.

 

[Temp]

Alright, thank you.

 

[Crepe]

Just measure your tank out in Decimeters and convert that to cubic decimeters which is equal to a litre. A close approximation to the gallon is 3.5l. I just use 4.

 

[taylorodw]

The website that Thincat linked suggests measuring the distance from front to back at the widest and most narrow points, then averaging it.

That is to say, if your tank is 14" from front to back at its widest, and 10" from front to back at its most narrow, then 14+10=24, 24/2=12, so use 12" for the calculator.

It's imprecise but like MG said, the 5 or so gallons won't make a huge difference unless your tank is very small

Good luck!

 

[Tildar]

For what it's worth, here is the aquarium volume calculation site that I really like.

Aquarium System Volume Calculator

 

[thincat]

Tildar, nice link, thanks for posting.

 

[Temp]

Oh, thank you Tildar. Now I know my tank is a bowfront, 1.6 gallon tank.

 

[Mark Hewitt]

For tanks as small as the ones you are talking about, by far the most accurate way will be filling it up from a measuring jug or something else you know the size of (e.g. 2 litre pop bottle)