I'm in SoCal but I can't do too many orchids in trees since our water odd liquid rock.

Do you mean the water is high in dissolved minerals?

Yes... very high in dissolved minerals and salts...
I use RODI water indoors but that's impractical for tree watering.

Not all orchids are sensitive to dissolved minerals and salts. Just find those that aren't sensitive.

Which ones aren't sensitive?
Any leads?

I would love to live some where that I could have orchids in a tree

Catts, Paphs, Phals, Cyms, Vandas, Papilionanthe, and Bulbophyllums, just to name a few.

Just find some that are temperature tolerant, and stick them on the tree.

There are some epiphytical Cymbidiums, btw. Same with Paphs, but the issue with Paphs is that the ones sold in the hobby that can tolerate cold, are not epiphytes.

There might be a few species of temperature tolerant Phals as well. I wouldn't try the hybrids.

If you can find a phal that suits your climate that isn't an epiphyte you can use basket lining coir or something similiar to create a 'pot' in the fork of a tree. Wire it on tight and it will grow happily and it won't matter if it's not really epiphytic.

My water kills catts and phals...at least they ones I've tried...
My cyms are doing well enough so far...
I haven't tried any of they other ones yet though...
There are? Where would I find a cymbidium like that?
Any cold tolerant orchids that grow in the leaf litter in the crotches of trees?

I don't think that your water is killing the Catts and the Phals. I think there are other factors at play.

Cymbidium aloifolium is actually an epiphyte or lithophyte. Sometimes it can be found as a semi-terrestrial as well. From the documentation, it's reputedly an intermediate to warm growing orchid. However, I really don't know what the plant can tolerate in terms of low end temperatures.

There are definitely orchids that grow terrestrially which can tolerate our cool winters here in SoCal. One of them is a native to China - Bletilla striata.

You may also try some of the other Bletilla species such as Bletilla formosana or Bletilla ochracea.