How do i know if my live rock is established/ready?

[Castaway6]

I know this is a basic question. But I'm talking about rock that I've had stored in a brute in saltwater in the garage with powerheads for months untouched.
Could it be safely established or would I need to do a water change and recycle it for a for days/weeks? What should I test for?

Thanks
Extra info: was all cleaned dry rock, I added bacteria and cycled for my current tank. Left the rest in the bucket and did 2 water changes the first month, then it all was untouched in a "cool dark" place (garage with lid) for maybe a year now. Its a 30 gal brute with 2 powerheads.
I'm not even sure of the salinity of the water as of now

 

[andrewey]

I would measure the salinity first and foremost. You may need to top off your RO water. After that, the easiest way to "test it" would be the same as any other live rock you've cycled- you can simply dose a known quantity of ammonia (e.g. 2ppm) and see that your rock can process it into nitrate completely in under 24 hours.

Normally, I would be shocked if the rock that's been sitting for that long isn't always cycled, however, in this situation with a possibly unheated container of unknown salinity, it's cheap and easy enough to double check. If it were heated and the salinity was "relatively" maintained, you're probably good to go