Need to change sand when changing tank?

[KCK]

Thinking of changing tank, from 6mm to 8mm thick.

Do I need to change the sand currently in my tank (6 mths)? I have some reefers that say that there will be toxic in the sand. What about the bacteria in the sand? Using the old sand would it not have the bacteria that I need for the new tank?

Toxic vs bacteria in the sand: Thats the question.

Anyone can advise please.

Thanks!

[sunny03]

wow bro so fast Upgrade ??

change to a 3*2*2 lar more heght den ur tank now

[ZeRoC00l]

Wash some of the old sand (top 1-1.5") with yr current sea water, and add to seed your new tank.

Should start off your bacteria growth in the new tank.