Work this one out. 600 1litre pots each with a lily bulb in, how many 150 litre bags of compost do I need after mixing every 150 litres of compost with 25 kilos of sharp sand. Do I hear 4? wrong! it is bucket full short of 5. Perhaps a couple of litres on the floor. I think it is about time I went to the trading standards people.
It states on the bag 150 litres when packed. the bag never had any other room left in it. So something along the lines of 35 litres in each bag has evaporated since packing. I think I would have noticed the gap it was missing from.