Need New Sand?

[Keflan]

I have just got a new 70L tank and I am going to use it for my current cold water fish. After I have set it up and put them in their new tank I was thinking of turning my current cold water fish tank into a tropical tank.

I was just wondering if I had to replace the sand in the current cold water fish tank to put in new tropical fish?

Thank you.

 

[Keflan]

Anyone know?

 

[bshenanagins]

No you shouldn't have to change it, but I would sift it around to get any trapped gases into the column and get broken down.