Upgrading to a 90g reef

My advice.. toss out any substrate/sand and buy new sand. From my experience, that is the #1 killer of stuff in the aquarium during a move, reusing old sand. Disturbing the sandbed is the big no-no that can't be avoided during a move. When I moved, I tried to keep all my old sand.. turned into a huge nightmare that took many months to recover from and 90% of my SPS corals died.

Easiest way to move corals without loss is to move them to another established tank (yours or even a friends) while your new tank gets setup and cycles. If that isn't an option, just getting a few rubbermaid bins from Wal-Mart with a powerhead, heater, live rock, and light will be more than enough to sustain most corals and other livestock for days/weeks. I know one local who has his garage full of bins in anticipation of setting up his 225G tank.. project has been going on for 2+ years now (keeps renovating the house/changing plans on tank location/solar tube lighting), and all his fish and corals are still fine in the garage in the bins.

I am sure there is more I am forgetting to mention... oh ya, like have as much pre-made SW ready at home as you can, and lots of dry towels because there is always water on the floor when doing moves. Save whatever water you can out of the old tank, but as soon as you start disturbing the sand and the water gets dirty, stop collecting that water and use what you have at home to finish filling up the tank when you get it home.

With the sand, all the critters that live in it live at certain depths. In my case, I had a deep sand bed, so I had a lot of "layers" of different life. When you disturb 200lbs of sand, take it out of the tank, put into buckets, and put back in the tank, all those critters that lived at certain levels of the sand get all mixed up, and the ones that lived near the top get crushed and killed in the process, causing things like ammonia spikes which SPS corals really do not like. On top of the die off from microfauna and bacteria you have all the built up detritus in the sand that you let loose into the water.

So... to say it short, even if you only have a few corals, the price of dry sand is so cheap there is no reason not to replace it compared to the cost of life/corals in the tank. You could go the cheap route and go with the Home Depot pool filter sand (silica free type) for like $5 a bag. Any dead/dry sand will become live sand in a short time if placed with live rock in a tank and going from dead to live doesn't cause any real issues as long as you pre-rinse it, short of reduced bio filtration, compared to the issues caused by going live to dead to live again.

One note on adding sand to an established tank.. always add small layers, no more than 1/2" at a time, this allows all the critters that live at certain depths to move upwards accordingly without getting crushed, which would happen if you add too much at once.

Awesome advice Ace. I will use it as well when i upgrade. Thanks.