I'm looking at a job bidding on 5000 seeding trees bought as your typical forestry seedling plugs (412's) and transplanting them into 1.5" x 7 inch cone-tainers for a trade show. The problem is that there is only about 1/4" space around the seedling. How do I fill this narrow a space efficiently? My first thought was to use a mix of sand and very fine peatmoss, but this doesn't flow evenly enough. My second thought is to get a slurry pump, and repeatedly fill and let drain the cells. Anyone done anything like this.