Tank Upgrade Size Difference

[JSchwarz]

I'm going to be going though the process of upgrading from a 4 year old established 30 gallon tank w/sump to a Red Sea 625 (133 gallon) in the next month or two. I fortunately am placing the new tank on the opposite side of the room, so I can have them up at the same time and transfer things at my own pace until everything is out of the old tank. I'm contemplating the timeline I should use to transfer to have the least negative affects on the coral. The tank is mixed as I have some soft corals, LPS, SPS and both RFA and BTAs. My current rock is around 30 lbs of Marco rock from the start of the tank. All of this rock will make it to the new tank which will have new around 100 lbs of new dry Marco rock. I'm thinking of these possibilities:

Option 1
a. Cycle new tank. Add a little sand and some marinepure from my current tank.
b. Move rocks with soft coral on them after cycle to help establish new rock. Move current fish.
c. Move LPS when Soft corals seem to be doing well.
d. Move SPS and anemones if LPS are doing well.

Option 2
a. Cycle new tank
b. Move everything in one go with the hopes that the 30lbs of established rock will be enough to keep the tank stable since the total bioload of the tank would not change.

I can see potential positives and negatives to both approaches. Option 1 seems safer, but It could be destabilizing to my current tank before everything is out which could cause it's own issues. Also more work and monitoring. Option 2 seems risky for some of the more sensitive corals and anemones, but may help the new tank get established faster. I would add additional fish slowly with either option. I'll probably start a build thread to document whatever I do.

Any opinions or experience from doing large upgrades would be appreciated.

 

[ATB USA]

Option 3: Cycle the new rock now in a tub. Then when you put the new tank up you can do it all at once and it will be like a water change. You will have all cycled rock and water. The light change will be the thing to watch for the corals.

 

[JSchwarz]

Option 3: Cycle the new rock now in a tub. Then when you put the new tank up you can do it all at once and it will be like a water change. You will have all cycled rock and water. The light change will be the thing to watch for the corals.

I am going to try to do that. I am going to be mocking up my aquascape before the tank is set up and put it into a tub after its pieces are glued together. For the light I'm going to try to rent a par meter when I set everything up. I want to measure the new tank and set the lights where I think they will need to be long term, then take measurements in my current tank and try to place the corals where they will be getting a similar amount of PAR and flow as best I can and use acclimation mode.