What filter do you get?

I strongly recommend using the OEM filter for your hydro-Gear transmission. Fram filters a horribly built filters with cardboard end caps, plastic bypass valves, very weak shell, cheap paper media....

they seperate the liquid solvent from powdered solid solute

They filter out some THC, but they do not filter out the entirety of it. A sizable portion still makes it past the filter.

You cant filter it out. you desalinate water through evaporating the water out of the salt.

You don't change the filter on a sand filter, you back wash it. Unless you mean how to you change the sand in a sand filter. This is done by removing the multi port control from the top of the unit...