Calculating Tank Volumes & Filtration Info

Graham · #1 (**permalink**) 02-01-2008, 10:03 PM

CALCULATING TANK VOLUME

From a few recent threads on here it seems that some people don't know how to do the simple maths required to calculate the volume of a tank, or in at least one case possibly don't even know the meaning of the word "volume"!
So maybe this would be a good time to explain it, and at the same time also explain how to calculate the volume that your terrapins require, it's not rocket science but it is something that every turt owner needs to know.
Maybe this could even be made a sticky so I don't have to type it out every time the question comes up?

If you live in the UK or anywhere else in Europe, or most places in the world apart from the USA, then it's best to measure the volume of a tank in litres. Gallons in the aquarium world generally refer to US Gallons which are different to Imperial Gallons and it's potententially confusing, a litre is a litre wherever you are (unless you're in the USA in which case a litre is a liter)

So to calculate the volume of any tank in litres, first measure the length, width, and depth in decimetres (a decimetre is 10cm, therefore a metre is 10 decimetres). Then multiply L x W x D to give the answer in litres.

To work out how much water volume (note that's water volume which is different to tank volume) your turts require you need to measure them, you do this the same way as you measure tortoises which is to measure the Straight Carapace Length or SCL. The correct way to measure is in a straight line from the front edge to the back edge of the carapace (upper shell), ignoring the curve of the shell and the head and tail.

When you know the SCL (in inches) multiply it by 40 to give the minimum water volume required, eg a 2" turt will require a minimum 80 litres, a 3" 120 litres, 4" 160 litres etc...
If you have more than one turt then allow 40 litres per inch for the biggest one, plus 20 litres per inch for each additional turt.
Remember that these are minimum amounts, more is always better!

When you come to select a tank you have to bear in mind that in most cases you won't be able to fill it right to the top, so you need a bigger tank volume than the required water volume, adding 25-30% to the water volume should give the approximate tank volume required.

FILTRATION

This is a subject that keeps coming up again and again, new keepers in particular often fail to appreciate the importance of adequate filtration, and just how much filtration is required for even the smallest turts.

Virtually all the filters on the market are designed for use with fish, and fish waste is very different to turt waste, a filter designed to deal with a few fish will struggle to cope with a couple of turts in a similar size tank, their waste is bigger and heavier, and they produce a lot more of it!

Failure to filter turt water correctly results in the buildup of toxic chemicals, mainly ammonia and nitrite, and in high enough concentrations these can kill your turts or at the very least make them very sick.

Amongst experienced keepers it's generally accepted that the more filtration you can provide the better, there's no such thing as too much, water can never be too clean! This means the use of large capacity external filters, filled with bio-media on which beneficial bacteria grow and break down the toxic chemicals into less harmful ones.

Rather than rambling on simply repeating information that is already available elsewhere, HERE you can find an excellent article on filtration listing the pros and cons of every type of filter, full explanations of the purpose of different types of filter media, water additives, testing of water, pretty much everything you need to know.

Drummerkid · #2 (**permalink**) 02-01-2008, 11:23 PM

Nice One Grahem, thats very usefull

Katiexx · #3 (**permalink**) 02-01-2008, 11:31 PM

nice thread hopefully will get made a sticky!

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