so my customer (the one that gave me his old salt tank) just called me and told me he is getting out of the hobby and said i can have all of his fish and rock work (he doesnt have much) a few fish and prob like 10-15lbs of rock work. but the problem is that i dont have a tank setup yet. what is the best way to get his fish and keep them alive or do i have to cycle the tank and everything. i would have to set up a temp tank, seeing i dont have money yet to set up the big one yet.

what is the bare min of stuff i would need to get a temp tank up and running?

i have a pump and a ocean clear filter and the main tank and also a 30gal sitting empty,

can i set up the 30gal and just put the ocean clear on it with some live rock and do that or is it just a waste?
thanks

I think you'd be ok with real saltwater you can buy at fishstores. Catlina or something like that. If it'd be only live rocck, you'd be ok. with freshly set up water, but you'd loose probably most all the coralline algaes.( if there's any)
You could set up you 30G that way. If there's a saltwater store near to you, ask them for some"used" saltwater, and there you go.

so like when they clean out there tanks maybe?

and well the tank was used as a fresh tank like 6 months ago and has been empty since.

but wont my tank go thro a cycle period like fresh and well i dont want the fish to die.

Whenever you move a tank, or move water from one tank to another, there's a small mini cycle almost every cases. Most of them are fast, and ammonia, nitrite won't reach toxic levels.
Now I only heard that those real saltwater you can buy,you'll be able to set up a system right away, so you don't have to cyccle. But IMO it'll will cyccle but it'll unnoticable for your livestock. Mucch safer thana freshly mixed set up.

It'd be the perfect set up for you. Live rock,live sand, and used saltwater.

it'll be ok right now.