I just moved a 180 that I got from a friend, 4 weeks ago today. The post is long, so forgive me, but it directly relates to your move.
I started at 10 in the morning and, by 7, everything was done. It took about 2 hours for moving the tank with the help of friends. The rest of the time was spent dissasembling equipment and loading the truck, then unloading and reassembly. It would have taken less time if I'd just moved everything instead of splitting it between home and tanks at my office.
It has 200 pounds of sand and about 300 pounds of rock total.
There were 3 fish, 2 soft coral colonies (polyps and rocordia), one large leather and one baby leather. There were very few inverts, a few crabs, 2 snails, a cucumber, 5 serpent stars, and 3 large feather dusters.
The tank was lightly stocked because of die off due to hurricane wilma. Moving the livestock was the simplest part of all, so if your tank is stocked normally, it won't be a greater burden.
The tank was on an island, so I had to build a stand prior to moving it. Other than that, here is what I did:
I bought 4 tan colored 18 gallon rubbermaid style tubs from Target. I also used 3 12 gallon tubs that I already had, along with a cork bait bucket with a battery operated air pump (you can use the styrofoam or plastic bait buckets, a 5 gallon pail, or whatever).
this is the style tub:
This is the style bait bucket you might use:
Disconnected the chiller, the mag drive return pump, and the lights. The live rock went into the 12 gallon tubs and into 2 of the 18 gallon tubs. removed the canopy.
Rocks without coral were covered with paper towels that were then soaked with water from the tank. Rocks can stay fresh as much as 10 hours this way. Sponges will die when exposed to air, but most other life on the rock survives. In fact, a serpent star had hidden inside a cavity in a large rock and I didn't notice him until 3 hours later when I put him in a tank at my office. He is doing just fine a month later.
Rocks with corals need to be kept submerged and these were the rocks placed in the 18 gallon tubs.
Once the rock was out, the fish and invertebrates were next. The water gets cloudy from moving the rocks, so you might want to let it settle for about an hour to an hour and a half. This is a good time to take apart wiring, pack bulbs (better than i did, though none broke), plumbing, and so on. During this time, empty the sump. Mine is a 4o gallon breeder, smaller than your 70.
After catching the fish and inverts and then placing them in the bait bucket, it was time to drain water out of the main display. I just siphoned it out because I was having it replaced with a delivery of fresh, filtered new ocean saltwater delivered by exotic aquatic's Simon.
At this point, I disagree with Tiger-eyed. I saved as much sand as possible and left it covered with saltwater. I put it in the tank ASAP after I'd stored the live rock in tanks at my office. If I'd gotten the saltwater delivery that day (or mixed it myself), I would have put the rock into the tank as soon as the sand was in.
The reason I saved the sand is because it was from a well established system (5 or 6 years, i can't remember which), with lots of live rock. Four weeks later, the sand is full of worms, pods, and baby snails. When a population die off occurs, many of these species leave eggs (in the form of cysts) that hatch later. In a healthy sandbed (from a tank that is not in decline), there are tiny creatures all through the sand.
As another example, the 75 gallon in my inner office at work lost all it's corals and fish in one of the 2004 hurricanes where the power was out for a week. I'd gotten live rock and live sand from three different oceans. It was my ultimate reef, you know?
Well, everything was dead, so I cleaned the rock and went through eleven or twelve water changes once I could get fresh oceanwater from LFS again. I put fish (only) back in it once the die off had been cleaned up. A hurricane a couple of weeks later knocked the power out for another week. I bought a bunch of battery powered air pumps but everybody still died.
I restocked it (fish only) one last time and then Wilma killed everything but Mr. Tang. When i moved him to the 180 gallon tank, the pod, worm, and snail population EXPLODED. After the tank died 3 times, it has more diversity than ever.
Save your sand.
The more species you have successfully living in your captive reef, the healthier and more stable that ecosystem is.
Also, a tank DOES cycle again when you break it down and move it. This includes a nitorgen cycle (ammonia spike, nitrie spike, nitrates) and an algae cycle, your diatoms, cyano, hair algae, etc, and this is normal. Reusing the already colonized live sand will shorten the nitrogen cycle considerably because most of the bacteria will survive the move.
My 180 gallon had completed its "mini" nitrogen cycle, or "recycle," whatever you want to call it, in about 36 hours. It may have been less, but I didn't get to check the levels Monday morning before work.
I hope this helps and, remember, the advice is exactly worth you paid me for it, so it won't hurt my feelings if you don't agree with it!
