On Sat, 30 Jan 2016 07:39:18 -0600, "Terry Coombs"
wrote:

The question was what to use to keep soil from filtering into the
gravel bed while allowing water to pass , which has been answered . I'll be
picking up a roll of landscape fabric today .

Is the pipe already installed? If not, I'd use a pipe sock for the
perforated pipe. That prevents dirt from dirty gravel seeping in or
from the surrounding soil under the pipe.

After the gravel, the landscape fabric adds less chance of soil over
the gravel from washing down into the pipe, too.

The fabric can be found in various densities and thread counts. Some
with a thicker mil than some others. The drainage will vary.

Given what you say and if I remember your project photos building
block walls on the new foundation, I doubt you will have any serious
water concerns.