diff --git a/system/hosts/Styx.nix b/system/hosts/Styx.nix
index d3b5c6b..6cb83e7 100644
--- a/system/hosts/Styx.nix
+++ b/system/hosts/Styx.nix
@@ -23,14 +23,12 @@ in
       keep-outputs = true;
 
       substituters = [
-        "https://attic.cache.daniel.sx/nifoc-systems"
-        "https://nifoc.cachix.org"
-        "https://nix-community.cachix.org"
+        "https://attic.cache.daniel.sx/nifoc-systems?priority=1"
+        "https://nix-community.cachix.org?priority=2"
       ];
 
       trusted-public-keys = [
         "nifoc-systems:eDDqVP5BFR6/1KvXbF9oUL8JahDdmbrsYtxlQ57LOTU="
-        "nifoc.cachix.org-1:ymuftq7RgN/lf/iWXFK8gpwDSAGFaGBeliWe9u6q8II="
         "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
       ];
 
diff --git a/system/hosts/adsb-antenna.nix b/system/hosts/adsb-antenna.nix
index 99ddf31..ef5c4d0 100644
--- a/system/hosts/adsb-antenna.nix
+++ b/system/hosts/adsb-antenna.nix
@@ -28,16 +28,14 @@ in
       auto-optimise-store = true;
 
       substituters = [
-        "https://attic.cache.daniel.sx/nifoc-systems"
-        "https://attic.cache.daniel.sx/nifoc-ci"
-        "https://nifoc.cachix.org"
-        "https://nix-community.cachix.org"
+        "https://attic.cache.daniel.sx/nifoc-systems?priority=1"
+        "https://attic.cache.daniel.sx/nifoc-ci?priority=2"
+        "https://nix-community.cachix.org?priority=3"
       ];
 
       trusted-public-keys = [
         "nifoc-systems:eDDqVP5BFR6/1KvXbF9oUL8JahDdmbrsYtxlQ57LOTU="
         "nifoc-ci:JpD9zqVQi8JuS7B8htPDOQZh08rhInMnGFS9RVhiuwk="
-        "nifoc.cachix.org-1:ymuftq7RgN/lf/iWXFK8gpwDSAGFaGBeliWe9u6q8II="
         "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
       ];
     };
diff --git a/system/hosts/argon.nix b/system/hosts/argon.nix
index 0dd310b..4ff691b 100644
--- a/system/hosts/argon.nix
+++ b/system/hosts/argon.nix
@@ -46,16 +46,14 @@ in
       auto-optimise-store = true;
 
       substituters = [
-        "https://attic.cache.daniel.sx/nifoc-systems"
-        "https://attic.cache.daniel.sx/nifoc-ci"
-        "https://nifoc.cachix.org"
-        "https://nix-community.cachix.org"
+        "https://attic.cache.daniel.sx/nifoc-systems?priority=1"
+        "https://attic.cache.daniel.sx/nifoc-ci?priority=2"
+        "https://nix-community.cachix.org?priority=3"
       ];
 
       trusted-public-keys = [
         "nifoc-systems:eDDqVP5BFR6/1KvXbF9oUL8JahDdmbrsYtxlQ57LOTU="
         "nifoc-ci:JpD9zqVQi8JuS7B8htPDOQZh08rhInMnGFS9RVhiuwk="
-        "nifoc.cachix.org-1:ymuftq7RgN/lf/iWXFK8gpwDSAGFaGBeliWe9u6q8II="
         "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
       ];
 
diff --git a/system/hosts/mediaserver.nix b/system/hosts/mediaserver.nix
index c2bd5dc..ebb9649 100644
--- a/system/hosts/mediaserver.nix
+++ b/system/hosts/mediaserver.nix
@@ -59,16 +59,14 @@ in
       auto-optimise-store = true;
 
       substituters = [
-        "https://attic.cache.daniel.sx/nifoc-systems"
-        "https://attic.cache.daniel.sx/nifoc-ci"
-        "https://nifoc.cachix.org"
-        "https://nix-community.cachix.org"
+        "https://attic.cache.daniel.sx/nifoc-systems?priority=1"
+        "https://attic.cache.daniel.sx/nifoc-ci?priority=2"
+        "https://nix-community.cachix.org?priority=3"
       ];
 
       trusted-public-keys = [
         "nifoc-systems:eDDqVP5BFR6/1KvXbF9oUL8JahDdmbrsYtxlQ57LOTU="
         "nifoc-ci:JpD9zqVQi8JuS7B8htPDOQZh08rhInMnGFS9RVhiuwk="
-        "nifoc.cachix.org-1:ymuftq7RgN/lf/iWXFK8gpwDSAGFaGBeliWe9u6q8II="
         "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
       ];
 
diff --git a/system/hosts/tanker.nix b/system/hosts/tanker.nix
index 8f9a4a2..406ddce 100644
--- a/system/hosts/tanker.nix
+++ b/system/hosts/tanker.nix
@@ -74,16 +74,14 @@ in
       auto-optimise-store = true;
 
       substituters = [
-        "https://attic.cache.daniel.sx/nifoc-systems"
-        "https://attic.cache.daniel.sx/nifoc-ci"
-        "https://nifoc.cachix.org"
-        "https://nix-community.cachix.org"
+        "https://attic.cache.daniel.sx/nifoc-systems?priority=1"
+        "https://attic.cache.daniel.sx/nifoc-ci?priority=2"
+        "https://nix-community.cachix.org?priority=3"
       ];
 
       trusted-public-keys = [
         "nifoc-systems:eDDqVP5BFR6/1KvXbF9oUL8JahDdmbrsYtxlQ57LOTU="
         "nifoc-ci:JpD9zqVQi8JuS7B8htPDOQZh08rhInMnGFS9RVhiuwk="
-        "nifoc.cachix.org-1:ymuftq7RgN/lf/iWXFK8gpwDSAGFaGBeliWe9u6q8II="
         "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
       ];
     };
diff --git a/system/hosts/weather-sdr.nix b/system/hosts/weather-sdr.nix
index 587b7b5..2808171 100644
--- a/system/hosts/weather-sdr.nix
+++ b/system/hosts/weather-sdr.nix
@@ -29,16 +29,14 @@ in
       auto-optimise-store = true;
 
       substituters = [
-        "https://attic.cache.daniel.sx/nifoc-systems"
-        "https://attic.cache.daniel.sx/nifoc-ci"
-        "https://nifoc.cachix.org"
-        "https://nix-community.cachix.org"
+        "https://attic.cache.daniel.sx/nifoc-systems?priority=1"
+        "https://attic.cache.daniel.sx/nifoc-ci?priority=2"
+        "https://nix-community.cachix.org?priority=3"
       ];
 
       trusted-public-keys = [
         "nifoc-systems:eDDqVP5BFR6/1KvXbF9oUL8JahDdmbrsYtxlQ57LOTU="
         "nifoc-ci:JpD9zqVQi8JuS7B8htPDOQZh08rhInMnGFS9RVhiuwk="
-        "nifoc.cachix.org-1:ymuftq7RgN/lf/iWXFK8gpwDSAGFaGBeliWe9u6q8II="
         "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
       ];
     };