brand new to FF question on creating filter

hello. i'm brand new. downloaded yesterday. so far i love it. i'm using FF to create maps for 3d models. diffuse, normal, etc... i just discovered that my new filters don't all have to be 600px by 600px ha! i can make them 4800x4800.

anyway, so in 3d, i have a 10ft tall 10inch diameter concrete column inside an old warehouse that i want to texture with a diffuse map and normal map.

i have created a filter which "adds" A&B, A&B are noises.

the concrete column is pitted, in other words, there are chips of concrete that have fallen off over the 60 years this building has been around.

what i am going for is to create normal map for showing those various chips and pits. but, i don't want to have too many of them spread all over the place so it looks like it's structurally unsound ha!

i've attached images showing the filter i came up with, then i photoshoped a copy to show fewer overall pits/chips, then attached what the filter looks like.

so my question is, what's the best approach to creating a mostly flat, but tileable filter with a small number of pits/chips?

thanks!

here is the filter in FF (which results in the top image)

EDIT: the gradient background is just something other than the bright pink background when there is nothing in the surface color

thank you sorry for the late reply!