Yes, I did a backwash of about 3000 litres.........I bought koi sand from global pools, think it's 3-5mm sand.
obviously this wont get all the dust out as when I started feeding the water back into the pond there mas a slight milkiness that still fed back into the pond, however that milkiness has since dissappeared, just if I look at the water now, it's pretty clean at the top, just cannot see the bottom all that lekker and when I see the fish at the bottom they seem dirty compared to at the top.
Think I may have a bit of dirt at the bottom as I had a submersible in the pond while I was sorting out the filtration system.
I wish one got the ash stuff you get for settling dirt in a pool for a pond....altho it would be useless with all the fish moving around.
Just I have this lekker filtration system setup now, so really wish my water was crystal clear