Code of Practice for keeping turtles in captivity in NSW- NSW Government Office of Environment and Heritage After looking at the Code of Practice (the Code) for Reptile Keeping in NSW I've done some thinking and actually worked out what I think is the ideal formula for working out how many turtles can be housed in tanks or ponds. This formula is realistic and not 'overkill' or overcrowded like the proposed tank dimensions in the NSW Code. Part of the problem with the Code is the way they calculate the tank size. They look at the Straight Carapace Length (SCL) of the turtle versus 'floor area'. I don't agree with this. SCL is OK but I have always preferred to use biomass or body weight. The reason for using mass is that some turtles of the same length are heavier than others and therefore would produce more waste. So to put the code into perspective I have calculated the requirements for some of my turtles. The results are surprising. For example - in the Code it states that 1 to 2 hatchling/baby turtles up to 60 days old must be housed in a tank that is 20cm x 30cm x 5cm deep. So for me, if I have one clutch of 20 turtles I would have to house them in 10 separate tanks. If that's not bad enough what would I have to do in the situation I have been in with more than 21 clutches of eggs hatched? I would have to set up 146 tanks to accommodate my 291+ baby turtles! This would be impossible! At the other end of the spectrum the code states that up to 5 Painted turtles, Irwin’s Turtles or Broad-shelled of up to 20cm SCL or 5 Eastern Snake-necks and Macleays up to 10cm can live in a 120cm x 45cm x 30cm tank (this is a standard 4ft tank) I think they have got this around the wrong way; if anything it should be 5 x 10cm Broad-shells or Irwin's etc. or 5 x 20cm Eastern snake-necks etc. Either way, I think this tank would be really overcrowded! The code doesn’t really say much about filtration except to say that “Water in aquatic enclosures must be adequately filtered or regularly changed to ensure that waste does not build up and quality is maintained”. This is very broad and I think they need to elaborate to explain what ‘adequate filtration’ is. So, now for my simple formula – The turtle’s body weight should not exceed 1kg per 100 Litres of water for long-term housing or hospitalisation. This means approximately 1% of the tank is occupied by turtles. This should still be the maximum you would want to house in an enclosure to ensure that the water stays clean with ‘adequate filtration’ or regular water changes. Some examples are – 200L tank = 1 x 2kg turtle will be comfortable or 5 turtles of up to 400gms or 10 turtles of up to 200 grams etc 30L hatchling or hospital tank = 1 x 300gm turtle or 60 x hatchlings at 5 grams each 10L hatchling starter tub = up to 20 baby turtles at 5 grams each 9000L pond = up to 90kg of turtles of various sizes. This means that you can collectively weigh a bevy of turtles, work out the litres in your tank and from that you can determine if you can add more turtles or if you need to take some out. In the case of larger turtles it would be ideal if the width of the tank/pond is twice the length of the turtle's shell to ensure it can move freely, with the minimum recommended width being 2ft wide.