New tank, old rock, freshwater soak

[Protodad]

Weird question. I picked up sand from a freshwater tank. Rock from various sources (dead, old live, fresh live).

Setting up a new 120 tank with lots of time and patience. I’m putting cold (68f) rodi in the tank with the plan to mix in salt after. I’m not planning to do a fast cycle with all the likely dead matter going in the tank. I’ve noticed a lot of bristle worms dying in the freshwater.

is there some benefits to a cold freshwater soak, assuming I’ll do a full cycle and clean (filter and skimmer) the water prior to adding the salt and heat or should I just get on with it and the standard cycle? The

 

[biophilia]

The only benefit (or reason) to do the freshwater soak would be to kill all invertebrate life in the live rock (like potential pests such as aiptasia), or beneficial organisms like bristle worms, copepods, amphipods, etc.