Old sand to new tank
 

Is it a good idea to put my live sand in old tank to a new tank?

Generally not actually. Depends on the age of sand but it's best to think of that stuff having a finite lifespan.

Best to use new, but if you really want to use the old sand make sure you rinse the snot out of it and prepare for a cycle in your new tank.

What size old, what size new, how old is the sand, and will you be adding more (new) sand to it?
I added all the sand from a 75g into a 155g, no issues. It can go terribly wrong though, so fill in the questions above and that will give a clearer picture of wat you want to do.

Hi sorry for hyjacking the thread, I'm going to be upgrading to a 90g soon my old tank would be about 6 mounths old why could i not take the top 1 inch and not use that but use the bottom 1 inch?

I mixup my sand every time I do a water change, by that I mean that I use a siphon to clean the sand. So definitly the top inch or so is clean every 7 - 14 days, but that is where the ditris sits and I can see that to use it you should boil and rinse very good. The bottom 1 inch or so is where most of the good stuff would be anyways as long as it is not suficated by the ditris. I have taken sand from my DT and started a new sand bottom in my daughters tank a month back with no troubles.

Bill

It is just from a 55 to 65.
The sand is ~2" and less than a year old
Thanks for all advice.

Jackie, I think you'd be fine moving it over to the new tank. If you're concerned, rinse it with the old tank water just to clean it up a bit, that will preserve the existing bacteria.