What's these rusty looking spots?

[Phillybonker]

If you find out over the winter or early next spring that you have to move your guerilla grow somewhere else at least you do not have a lot of money involved in a quality source of calcium plus other nutrients just for a basic test.

Yep nothing worse than spending hours/days prepping a spot and hauling in compost only for the situation to change and got to abandon the area. Been there before, it sucks.