You have an anonymous tip, which standing alone is not enough. Then you have corroboration in the form of actual trace amounts of cannabis, drug related materials including a package that at one time contained seeds, and THE ELECTRIC BILL. When taken together, it is more probably than not that a crime was being committed there - i.e those missing seeds were being cultivated.
Now, how do you know the tip was truly anonymous and not offered by a confidential informant?

