True ghost shrimp do not need brackish water. Many machrobrachium and caridina species do, but not paleamonetes, which reproduces entirely in fresh water. I have bred many of them, and I can attest that they don't need salt.
But there are other shrimp also called Ghost, so that might be confusing. But those sold for feeders, that are native to the US, are fresh water. The trick is raising the larvae, which need microscopically small food items for the days they are zoeys, which is the name for the larvae.
The eggs will get bigger, and slowly get lower down on the shrimp. Once they are underneath her, she will fan them with her swimmerets to keep them clean and shortly before she lets them go they may change colour a bit.
They'll be let go in about 3 or 4 weeks, and float to the top, if the don't get sucked into a filter. They quickly hatch, and at room temps, morph to shrimplets in about four or five days, if they can find food to eat while they are zoeys. I cultured single cell algae for mine.. aka greenwater, from pure species disks, and poured about 50 ccs of it into a 5 g breeder tank twice a day until they morphed. Used only a sponge filter, so they can't be sucked up.
The shrimplets hang near the surface in the day, sinking down to the bottom at night, rising again when the lights come on. For a few days they don't move much, but you can see the suggestion of legs, and the eyes are visible. If a microworm or other food comes within reach of the shrimplet you will see the tiny body jerk as it grabs for it, but they can't swim freely quite yet.
They need food items like microworms, or super finely crushed flakes.. totally powdered, in tiny, tiny amounts. One or two specks of powder is food for a day or so.
They moult often, you'll see the shed shells, might think they are dead shrimplets. They grow pretty fast and by the time they are quarter inch, behave much like adults, but spend much ,time at the bottom. They love to feed on a sponge filter, or wood, but will pick at anything.
They need a tank with plenty of biofilm, because that is the primary food source for the shrimplets after they morph, once they start crawling and swimming independently, until they are about a half inch in size. Even after that, biofilm remains a favoured food source.
Adult shrimp live, at best, maybe 18 months, you might get two years if the conditions are ideal, but a year is more likely. Need clean water, relatively cool temps, 70 F or so, and biofilm, more than anything. Sponge filters work great, or put a prefilter on a HOB type filter, sponge preferably.
Will eat anything, like shrimp pellets, algae pellets, fish flakes, microworms, frozen bloodworms and other frozen delights, like BBS.
They get darker with age, turn a bit orangish on the back, get some dark marks on the shells. Many have a bright orange band around each 'wrist' and a bright orange 'dash' mark on each tail fan segment. Not all have this marking but many of them do.
Charming little guys, and mostly pretty tolerant as shrimp go, if they are not injured when you get them. Some will be, as they are sold as feeders and thus not treated with much care.
They also prefer fairly cool water. Sometimes they don't do as well at higher temps.. I keep mine below 75, often around 70. They do well at that temp.