Running it for a few seconds in fresh should not kill the rock. If you then put it into the saltwater. Should still not experience a cycle.
If parameters are equal, go ahead and move them to the tank. They will appreciate the room and cover of the rocks.
When i do a full clean on my 40g or 20g, I also will take everything out and scrub the tank with tap water and then put it all right back in. This does not go for rock though.
Sounds like a deal!
As others noted, the tang and foxface will get too big for that system.
If parameters are equal, go ahead and move them to the tank. They will appreciate the room and cover of the rocks.
When i do a full clean on my 40g or 20g, I also will take everything out and scrub the tank with tap water and then put it all right back in. This does not go for rock though.
Sounds like a deal!
As others noted, the tang and foxface will get too big for that system.