If the 29 is a new tank, just take the gravel and filters off the 10 gallon and use it in the 29. The water carries pretty much no bacteria and is only good to keep a constant ph should you have a different ph in your tank and your tap water. You can use the water if you dont do many water changes so the change in nitrates is not too drastic...but for the most part, as long as you use the filters off the old tank you will be fine.