I picked up a large bag of perlite and I put down like 8 inches of it in my 10 gallon totes. And I translated them in it with the same soil I used in the 5 gallon buckets.20 gal bags, you can't over water them and you'r roots get to breathe
I had put fabric pots down in the buckets and then the soil so that made it easier to get them out if the buckets.