How can upgrade tank without causing a cycle??

[vokrey09]

My current setup is:
37gal high FOWLR
Fluval C4 Filter
CPR Bak Pak 2+ Skimmer
2 Hydor 425gph Powerheads
20lbs Live Rock
25lbs Live Sand

I am upgrading the tank to a 40gal breeder, which I want to start using to keep soft and LPS corals.

I need to know how I can safely get all the live rock, live sand, and livestock (about 5 fish, 2 shrimp, a handful of snails, and a starfish) setup in my new tank without causing a cycle.

In addition to the materials I listed above, I will be adding another:
20lbs of crushed coral sand
40lbs of dry rock

I have a 30 gal tank and three 5gal buckets to aide in the storage of materials during the process. What would be the best strategy to transfer everything over without causing a cycle. I would like to do it as quickly as possible so the fish don't get stressed

[bundybear1981]

IMO dump the old sand (or as minimum wash it really well, less one cup), start with all new sand and about 1 cup of the old sand to seed the new sand. If stirred up it will cause a new cycle.

The rock can be safely transferred to the new tank, keep it damp and it will be fine. It will seed the dry rock too.

Once you have transferred the rock and have your rockscape how you like it, move the fish, then inverts, then snails ( I say snails last to minimize the time you 'chase' the fish around to get all the snails.)

Some pointers are
1) ensure that the 2 systems are at the same salinity
2) the temperature is fairly close (closer the better)
3) Monitor the ammonia in case of any spike
4) Have NSW on hand to do water change should a spike occur.

Other pointers
1) Make sure you thoroughly wash the new sand and dry rock before adding it to the new tank.
2) Try to use RODI water when mixing your NSW, corals tend to be more sensitive to impurities then fish only tanks.
3) Take time to get the rockscape just right before moving the livestock to prevent stressing the fish post-move.

[ca1ore]

Is good advice. Conventional wisdom is to not reuse old sand, though I have done it to varying degrees over multiple tank moves and in most cases did not get a cycle. Depends a bit on the condition if the old sand. With my last tank upgrade (90 to 265) I reused all but the very lowest level of the old sand bed (it was not a DSB), but then installed new, well washed sand as the top inch of the new sand bed.