The mix sounds similar to one I got, general all purpose if this helps any. The ratios they pre mix have always worked great for me in the past. Being its general purpose meaning they mix it neutral for a range of things from carrots tomatoes to weed
. its black very rich and smells like good soil to me. The nose always knows lol
I always tailor amendments/ add things throughout and this always works for a good base soil to get started. I simply mixed in 15 litres of worm castings for starters, mj loves that chit.
I lugged 30 bags so far, I should of ordered some by yard. Might want to check a reference or two before ordering.
I'd be pissed if it was some soil that already been used or isnt fully broken down. That's despicable way to conduct business for real .
The sand that already exists might have some essential elements like silica, something soil has small percentages in, plants run out later into grow.
I might keep some in the mix. especially if there's a source of circulating water with sea life near by, lots of nutrients is in some sands. but lacks drainage and oxygen is more limited etc, far from the best medium on its own.