Don't see any problem with putting them in the sump.
But why don't you use the cocktailshrimp method? 1 Shrimp/50gallons. Just pop them in and let them rot.
This way the fish don't get gill damage from the NH3/NO2
Dan
All you need to start a cycle is something to decompose to get the bacteria growing. The decomposing shrimp would do that, and no fish would need to suffer.
Put the raw shrimp in the tank and let it/them sit in your tank for about a week. The shrimp will kind of rot and add ammonia to your tank. This is the beginning of your cycle and your tank will then start to grow the good bacteria and other stuff it needs to be established. Your nitrites will rise followed by your nitrates rising. Eventually your ammonia, nitrites and nitrates should fall and go to zero ideally. How long all depends on what you have in your tank now, substrate and rock.
This is it in a nutshell. Smarter people then me can go into the details of the whole thing. However you could do a search on this site that might answer your questions.
HTH
Scott
Go with the shrimp method, or just cycle your tank with uncured live rock. That is your best bet.
You do not want to use damsels. Besides, if you were to cycle your tank with damsels, you would have to use 30 of them because it is recommended you use 1 fish for every 5 gallons of water.
mkcsil18:
I'm brand new to this too, so I don't usually offer advice. I do know, though, that you can add shelled cocktail shrimp from the supermarket. HTH
claire
Yes on being able to find it at the supermarket.
To the other question. Is the live rock from the smaller tank cured? If so, this will not help cycle your tank. You need uncured live rock.