Going from a smaller to larger tank which isn't established

[azcummins]

I'm buying a 55 gallon tank that has been established for 2 years and all the levels are great, etc.

However, I found a 65 gallon tank (just the tank, nothing in it) that I'd like to move everything (sand, rock, fish, filters, etc) from the 55 gallon tank into the 65 gallon tank. Any reason why I couldn't just take everything from the 55 gallon tank and put it into the 65 gallon tank? The only threat I see is that I'd be stirring up the sand bed, which is about 2-3" deep so I could be releasing some nitrates into the water.

 

[tunerX]

With a deeper sand bed you can also release trapped gasses from the denitrification process. Pretty dangerous to fish, corals, and inverts. I would cycle it as normal and seed from the old tank.

 

[kittyhazelton]

When I moved from my 75gal to the 125 I did not use the old sand. Everything else was used from the old tank though. Saved me having to worry about stirring up nasty stuff in the sand. I'm keeping an eye on parameters and up on regular maintenance, but the worst I've got right now is a slight brown-algae bloom which my snails are doing a pretty good job at keeping under control. My fish and corals are doing fine.
With some caution I think you would be OK. just keep on top of the maintenance, maybe do more frequent water changes for a little while, and maybe you can mix some of the old sand with new sand to help seed it. or possibly try rinsing it out with some saltwater?

 

[azcummins]

I figured I'd put all the old sand in a bucket and wash it down with old tank water. This way if I release nasty stuff, it will get washed away before it goes in the new tank.

 

[Predator 1]

If your resources allow, buy a heavy duty Skimmer. It will "smooth" the transition for you, and look after your system in the future. Failing that, follow the regular maintenance schedules that have been mentioned. And good luck.

 

[Zygaena]

I figured I'd put all the old sand in a bucket and wash it down with old tank water. This way if I release nasty stuff, it will get washed away before it goes in the new tank.

I think it would be better not to wash our some of the old sand, maybe a fourth of it, and just transfer that into the new tank. Washing out the sand will also wash away the denitrifying bacteria in it which would help seed your new tank. Besides, simply moving sand into a new tank will release "nasty stuff" like alkaline pockets and hydrogen sulfide gases. Just don't do it while your fish are still in the old tank.

The last time I did this, I put a removable biofilter in the old tank, let it mature for three weeks, and put this in the new tank the same day I began the move. I also transferred and mixed a third of the old tank water into the new tank to minimize the "new water" stress on my livestock.