I would mix you're own soil its better. What I do is use peat free potting compost nothing expensive or even go to your local woods and get leave mulch/dirt. Then crush up limestone into small chippings (you can buy this in most garden centres if you want) and get some grit sand (this will have corse sand and small girt up to about 5mm included.
I Mix about
2 parts grit sand : 1 part compost : 1 part limestone chippings
Bake in oven at 200 degrees C for 2 hours this will remove all moisture and kill any bugs or fungi let it cool for a day in a clean tub.
clean any moist soil away from the root but be carefull not to damage root fibres, just remove soil leaving about 1-2 cm around root. Then get a nice tall and narrow clay pot fill about the bottom 1/4 with large limestone chippings for air and drainage and pot the cacti so its just below the level of the top of the pot.
Get some nice pebbles to cover the top of the soil so it looks pretty.
But dont water it for about 2 weeks let the plant recover from the stress as they dont like being moved.
one thing it would say is put it in a window where it can get some direct light, not all day, mine get indirect from dawn until 12:30 and direct light until about 18:30 and then back to indirect until dusk in the summer. In the wild peyotes grow in many different conditions from aluvial flood plain that recieved lots of water to desert cliffs where they grow out of cracks in the limestone and minimal water. Check this site out I found
Lophophora.info you will be able to see all the different conditions they are found in.