diff --git a/default_settings.lua b/default_settings.lua
index c211153..7d8bfd9 100644
--- a/default_settings.lua
+++ b/default_settings.lua
@@ -29,16 +29,22 @@ local settings = {
 	delete_item_on_clearobject = true,
 }
 
+pipeworks.toggles = {}
 -- documentation for toggles controlling pressure logic features.
 -- do not edit this file directly;
 -- instead, create pipeworks_settings.txt in your world directory,
--- and copy the uncommented lines from the block comment below into it.
+-- and copy the uncommented lines from the block comments below into it.
+--[[
+-- flow logic implementation.
+-- set to one of the following strings.
+-- "classic": classic mode written by VanessaE
+-- "pressure": pressure metadata based, written by thetaepsilon.
+--	has caveats such as water speed issues though.
+-- setting to nil inhibits all flow logic, useful for debugging ABM crashes,
+-- or for rendering the pipes purely decorative.
+]]
+pipeworks.toggles.pipe_mode = "classic"
 --[[
--- enable pressure logic mode instead of "classic" mode.
--- WARNING: this changes a few things, most noticeably how pumps work.
--- you'll want to make sure they're fed by an infinite spring.
-pipeworks.toggles.pressure_logic = true
-
 -- force-enable finite water handling mode.
 -- this changes the way that water node placement is handled;
 -- volume will always be preserved,
diff --git a/init.lua b/init.lua
index 9ce6a0f..e908bcc 100644
--- a/init.lua
+++ b/init.lua
@@ -15,17 +15,13 @@ pipeworks.modpath = minetest.get_modpath("pipeworks")
 
 dofile(pipeworks.modpath.."/default_settings.lua")
 -- Read the external config file if it exists.
-
-
--- please add any new feature toggles to be a flag in this table...
-pipeworks.toggles = {}
 local worldsettingspath = pipeworks.worldpath.."/pipeworks_settings.txt"
 local worldsettingsfile = io.open(worldsettingspath, "r")
 if worldsettingsfile then
 	worldsettingsfile:close()
 	dofile(worldsettingspath)
 end
-if pipeworks.toggles.pressure_logic then
+if pipeworks.toggles.pipe_mode == "pressure" then
 	minetest.log("warning", "pipeworks pressure logic mode comes with caveats and differences in behaviour, you have been warned!")
 end
 
diff --git a/pipes.lua b/pipes.lua
index 2acdfa9..602daab 100644
--- a/pipes.lua
+++ b/pipes.lua
@@ -213,7 +213,7 @@ pipeworks.pipes_empty_nodenames = pipes_empty_nodenames
 
 
 
-if not pipeworks.toggles.pressure_logic then
+if pipeworks.toggles.pipe_mode == "classic" then
 
 
 
diff --git a/pressure_logic/abm_register.lua b/pressure_logic/abm_register.lua
index a8e3abc..4019eef 100644
--- a/pressure_logic/abm_register.lua
+++ b/pressure_logic/abm_register.lua
@@ -10,7 +10,7 @@ local flowlogic = pipeworks.flowlogic
 -- see flowlogic.run() in abms.lua.
 
 local register_flowlogic_abm = function(nodename)
-	if pipeworks.toggles.pressure_logic then
+	if pipeworks.toggles.pipe_mode == "pressure" then
 		minetest.register_abm({
 			label = "pipeworks new_flow_logic run",
 			nodenames = { nodename },
diff --git a/pressure_logic/flowable_node_registry_install.lua b/pressure_logic/flowable_node_registry_install.lua
index 9bb9e9a..5cf1941 100644
--- a/pressure_logic/flowable_node_registry_install.lua
+++ b/pressure_logic/flowable_node_registry_install.lua
@@ -20,14 +20,14 @@ local insertbase = function(nodename)
 	if checkexists(nodename) then error("pipeworks.flowables duplicate registration!") end
 	pipeworks.flowables.list.all[nodename] = true
 	-- table.insert(pipeworks.flowables.list.nodenames, nodename)
-	if pipeworks.toggles.pressure_logic then
+	if pipeworks.toggles.pipe_mode == "pressure" then
 		abmregister.flowlogic(nodename)
 	end
 end
 
 local regwarning = function(kind, nodename)
 	local tail = ""
-	if not pipeworks.toggles.pressure_logic then tail = " but pressure logic not enabled" end
+	if pipeworks.toggles.pipe_mode ~= "pressure" then tail = " but pressure logic not enabled" end
 	--pipeworks.logger(kind.." flow logic registry requested for "..nodename..tail)
 end