Combining tanks

[DulcyDoll]

I have a 24 gallon nano-cube Deluxe that has been set up for 6 months, and yesterday I bought a 12 gallon Nano-cube deluxe that has been set up for 3 years. My intention is to move the 12 gallon into my 24 gallon. The 12 gallon has 13lbs of liverock that is covered in coraline algae, mushrooms of various colors, an elephant ear mushroom, zoanthids of different colors, and a Purple Tip Anemone (debating on keeping him, though he looks VERY healthy) it has tons of baby star-fish (including brittle stars) stamotella snails, turbo-snails, hermit crabs, and little bugs all over.(bought the 12 gallon nano, and stand for $150! thought it was a great deal! considering the tank and stand alone is over that price)

I'm not sure how to go about moving the 12 into the 24 though. I tested the water today, and both tanks are great, the 12's salinity is a bit lower than mine, but it needs a top off so I can add salt to that to bring it to my level. There is one main piece of rock that has most of the corals on it, and i know i need to acclimate slowly to get them used to my tank water before putting them in..but i am paranoid that i am going to kill everything. My 24 gallon has no coral in it at all. All i have is a Velvet Blue Damsel, an emerald crab, 8 turbo snails, and 2 Nassarius snails.

I am going to have to do some major re-arranging in the 24 to place the new LR, (which will make my damsel very angry..lol) Do I take the fish and crab out before i begin arranging things so they don't get over stressed or smushed? will removing them only stress them more? I am concerned as well because my tank has live sand and it appears the 12 has crushed coral, I was going to add some to my 24(to get some of the critters in it), but am not sure that I like it very much..

There are so many things to think about, but maybe I am over thinking it..the corals just look so sensitive and fragile that I am worried I will mess them up in the switch. Or that I will put them in a spot that they won't thrive.
If someone could point me to a place that I could get this info. or just give me personal experience's that would be more than appreciated.

[random]

I'm new at this, myself, but maybe can get things started.

re. live rock & soft corals:
2 weeks after we set up with live sand and hermits, got our (30 lbs) live rock. LR had pulsing xenia & 2 kinds of button polyps; Fish Dude threw in a spotted mushroom & a Kenya tree; and all have survived 2 months of my complete inexperience I'm assuming that if all these survived a >1 hour trip in a cardboard box with a few wet paper towels, and getting put directly into a new tank, that yours should be ok.

I was told that temperature & salinity (& pH?) are the #'s to look at when acclimating stuff.

just the experience we had, HTH.

[DulcyDoll]

Thanks. Temp and pH are the same, im working on the salinity.

Any advice on if i should remove my fish and crab before re-modeling my tank?