Introducing a second turtle to the tank

Question
Hi, I have an Australian long neck turtle which is about three years old and the size of a bread & butter plate.  We currently have it in a 1.5 x .5 x .75 tank half full of water with a resting rock.  Friends have found a turtle in their garden which is roughly the same size.  Can we safely put the stray turtle in the tank alongside ours or not?

Thanks,
Chrystal

Answer
There is not a ton of helpful information in this note- is the new turtles the same species, are the measurements metric or US, what kind is the new turtle?

In general...

- We do not want to crowd turtles. The habitat should allow about 10 gallons of water per inch of shell length, about 15L per centimeter. Overcrowdeing causes stress, aggression, etc.

- We do not want to mix species from different regions. Germs and parasites found naturally in one can make the other very ill.

- We do not want to mix turtles of different temperaments- some tend to be more aggressive than others, and the new turtle may fall in this category.

- Wild turtles are always stressed by captivity and carry parasites that can harm existing pets.

This is a lot of 'maybes' and 'coulds', it ultimately comes down to you and your views on pet-keeping.

Good luck!

ADDED: There is no dip or solution that will eliminate the risks of parasites or most diseases. Turtle dip solutions are a simple sulfa-based anti-biotic, and a very weak one at that. They are only moderately effective on some conditions and do not change the things mentioned at all.