Once I had a clear tarpoline again I put another batch of old potting mix on it. 30 13" pots. Not as much as last time, maybe 300L.
I added 3 barrow loads of dried, mulched cow manure until I was happy with the mix. It just stayed together when I squeezed it.
I have not covered it as we have had storm rain since late September.
This mix put it Tank bed No 1 20/4/2019