module things, jfc

code/modules/atmospherics/environmental/LINDA_system.dm

@@ -120,4 +120,5 @@
 	G.parse_gas_string(text)
 
 	air.merge(G)
+	archive()
 	SSair.add_to_active(src, 0)

code/modules/atmospherics/gasmixtures/gas_types.dm

@@ -129,6 +129,13 @@ GLOBAL_LIST_INIT(nonreactive_gases, typecacheof(list(/datum/gas/oxygen, /datum/g
 	name = "Pluoxium"
 	fusion_power = 10
 
+/datum/gas/miasma
+	id = "miasma"
+	specific_heat = 20
+	name = "Miasma"
+	gas_overlay = "miasma"
+	moles_visible = MOLES_GAS_VISIBLE * 60
+
 /obj/effect/overlay/gas
 	icon = 'icons/effects/tile_effects.dmi'
 	mouse_opacity = MOUSE_OPACITY_TRANSPARENT

code/modules/atmospherics/gasmixtures/reactions.dm

@@ -257,7 +257,7 @@
 		reaction_energy += gases_fused * FUSION_RELEASE_ENERGY_SUPER * (power_ratio / FUSION_ENERGY_DIVISOR_SUPER)
 		cached_gases[/datum/gas/tritium][MOLES] += gases_fused * FUSION_GAS_CREATION_FACTOR_TRITIUM //60% of the gas is converted to energy, 40% to trit
 		fusion_prepare_to_die_edition_rng = 100 //Wait a minute..
-		do_explosion = TRUE
+		do_explosion = TRUE			
 		zap_range = FUSION_ZAP_RANGE_SUPER
 
 	else if (power_ratio > FUSION_HIGH_TIER_THRESHOLD) //power ratio 20-50; High tier. The reaction is so energized that it fuses into a small amount of stimulum, and some pluoxium. Very dangerous, but super cool and super useful.
@@ -433,3 +433,30 @@
 		var/new_heat_capacity = air.heat_capacity()
 		if(new_heat_capacity > MINIMUM_HEAT_CAPACITY)
 			air.temperature = max(((air.temperature*old_heat_capacity - energy_taken)/new_heat_capacity),TCMB)
+	
+
+/datum/gas_reaction/miaster	//dry heat sterilization: clears out pathogens in the air
+	priority = -10 //after all the heating from fires etc. is done
+	name = "Dry Heat Sterilization"
+	id = "sterilization"
+
+/datum/gas_reaction/miaster/init_reqs()
+	min_requirements = list(
+		"TEMP" = FIRE_MINIMUM_TEMPERATURE_TO_EXIST+70,
+		/datum/gas/miasma = MINIMUM_MOLE_COUNT
+	)
+
+/datum/gas_reaction/miaster/react(datum/gas_mixture/air, datum/holder)
+	var/list/cached_gases = air.gases
+	// As the name says it, it needs to be dry
+	if(/datum/gas/water_vapor in cached_gases)
+		if(cached_gases[/datum/gas/water_vapor]/air.total_moles() > 0.1)
+			return
+
+	//Replace miasma with oxygen
+	var/cleaned_air = min(cached_gases[/datum/gas/miasma][MOLES], 20 + (air.temperature - FIRE_MINIMUM_TEMPERATURE_TO_EXIST - 70) / 20)
+	cached_gases[/datum/gas/miasma][MOLES] -= cleaned_air
+	cached_gases[/datum/gas/oxygen][MOLES] += cleaned_air
+
+	//Possibly burning a bit of organic matter through maillard reaction, so a *tiny* bit more heat would be understandable
+	air.temperature += cleaned_air * 0.002

code/modules/atmospherics/machinery/airalarm.dm

@@ -89,6 +89,7 @@
 		/datum/gas/oxygen			= new/datum/tlv(16, 19, 135, 140), // Partial pressure, kpa
 		/datum/gas/nitrogen			= new/datum/tlv(-1, -1, 1000, 1000),
 		/datum/gas/carbon_dioxide	= new/datum/tlv(-1, -1, 5, 10),
+		/datum/gas/miasma			= new/datum/tlv/(-1, -1, 2, 5),
 		/datum/gas/plasma			= new/datum/tlv/dangerous,
 		/datum/gas/nitrous_oxide	= new/datum/tlv/dangerous,
 		/datum/gas/bz				= new/datum/tlv/dangerous,
@@ -107,6 +108,7 @@
 		/datum/gas/oxygen			= new/datum/tlv/no_checks,
 		/datum/gas/nitrogen			= new/datum/tlv/no_checks,
 		/datum/gas/carbon_dioxide	= new/datum/tlv/no_checks,
+		/datum/gas/miasma			= new/datum/tlv/no_checks,
 		/datum/gas/plasma			= new/datum/tlv/no_checks,
 		/datum/gas/nitrous_oxide	= new/datum/tlv/no_checks,
 		/datum/gas/bz				= new/datum/tlv/no_checks,
@@ -125,6 +127,7 @@
 		/datum/gas/oxygen			= new/datum/tlv(16, 19, 135, 140), // Partial pressure, kpa
 		/datum/gas/nitrogen			= new/datum/tlv(-1, -1, 1000, 1000),
 		/datum/gas/carbon_dioxide	= new/datum/tlv(-1, -1, 5, 10),
+		/datum/gas/miasma			= new/datum/tlv/(-1, -1, 2, 5),
 		/datum/gas/plasma			= new/datum/tlv/dangerous,
 		/datum/gas/nitrous_oxide	= new/datum/tlv/dangerous,
 		/datum/gas/bz				= new/datum/tlv/dangerous,
@@ -145,6 +148,12 @@
 	req_access = null
 	req_one_access = list(ACCESS_ATMOSPHERICS, ACCESS_ENGINE)
 
+/obj/machinery/airalarm/mixingchamber
+	name = "chamber air alarm"
+	locked = FALSE
+	req_access = null
+	req_one_access = list(ACCESS_ATMOSPHERICS, ACCESS_TOX, ACCESS_TOX_STORAGE)
+
 /obj/machinery/airalarm/all_access
 	name = "all-access air alarm"
 	desc = "This particular atmos control unit appears to have no access restrictions."
@@ -155,6 +164,22 @@
 /obj/machinery/airalarm/syndicate //general syndicate access
 	req_access = list(ACCESS_SYNDICATE)
 
+/obj/machinery/airalarm/directional/north //Pixel offsets get overwritten on New()
+	dir = SOUTH
+	pixel_y = 24
+
+/obj/machinery/airalarm/directional/south
+	dir = NORTH
+	pixel_y = -24
+
+/obj/machinery/airalarm/directional/east
+	dir = WEST
+	pixel_x = 24
+
+/obj/machinery/airalarm/directional/west
+	dir = EAST
+	pixel_x = -24
+
 //all air alarms in area are connected via magic
 /area
 	var/list/air_vent_names = list()
@@ -189,6 +214,16 @@
 	. = ..()
 	set_frequency(frequency)
 
+/obj/machinery/airalarm/examine(mob/user)
+	. = ..()
+	switch(buildstage)
+		if(0)
+			to_chat(user, "<span class='notice'>It is missing air alarm electronics.</span>")
+		if(1)
+			to_chat(user, "<span class='notice'>It is missing wiring.</span>")
+		if(2)
+			to_chat(user, "<span class='notice'>Alt-click to [locked ? "unlock" : "lock"] the interface.</span>")
+
 /obj/machinery/airalarm/ui_status(mob/user)
 	if(user.has_unlimited_silicon_privilege && aidisabled)
 		to_chat(user, "AI control has been disabled.")
@@ -338,25 +373,25 @@
 				locked = !locked
 				. = TRUE
 		if("power", "toggle_filter", "widenet", "scrubbing")
-			send_signal(device_id, list("[action]" = params["val"]))
+			send_signal(device_id, list("[action]" = params["val"]), usr)
 			. = TRUE
 		if("excheck")
-			send_signal(device_id, list("checks" = text2num(params["val"])^1))
+			send_signal(device_id, list("checks" = text2num(params["val"])^1), usr)
 			. = TRUE
 		if("incheck")
-			send_signal(device_id, list("checks" = text2num(params["val"])^2))
+			send_signal(device_id, list("checks" = text2num(params["val"])^2), usr)
 			. = TRUE
 		if("set_external_pressure", "set_internal_pressure")
 			var/area/A = get_area(src)
 			var/target = input("New target pressure:", name, A.air_vent_info[device_id][(action == "set_external_pressure" ? "external" : "internal")]) as num|null
 			if(!isnull(target) && !..())
-				send_signal(device_id, list("[action]" = target))
+				send_signal(device_id, list("[action]" = target), usr)
 				. = TRUE
 		if("reset_external_pressure")
-			send_signal(device_id, list("reset_external_pressure"))
+			send_signal(device_id, list("reset_external_pressure"), usr)
 			. = TRUE
 		if("reset_internal_pressure")
-			send_signal(device_id, list("reset_internal_pressure"))
+			send_signal(device_id, list("reset_internal_pressure"), usr)
 			. = TRUE
 		if("threshold")
 			var/env = params["env"]
@@ -373,9 +408,11 @@
 					tlv.vars[name] = -1
 				else
 					tlv.vars[name] = round(value, 0.01)
+				investigate_log(" treshold value for [env]:[name] was set to [value] by [key_name(usr)]",INVESTIGATE_ATMOS)
 				. = TRUE
 		if("mode")
 			mode = text2num(params["mode"])
+			investigate_log("was turned to [get_mode_name(mode)] mode by [key_name(usr)]",INVESTIGATE_ATMOS)
 			apply_mode()
 			. = TRUE
 		if("alarm")
@@ -433,17 +470,39 @@
 	frequency = new_frequency
 	radio_connection = SSradio.add_object(src, frequency, RADIO_TO_AIRALARM)
 
-/obj/machinery/airalarm/proc/send_signal(target, list/command)//sends signal 'command' to 'target'. Returns 0 if no radio connection, 1 otherwise
+/obj/machinery/airalarm/proc/send_signal(target, list/command, mob/user)//sends signal 'command' to 'target'. Returns 0 if no radio connection, 1 otherwise
 	if(!radio_connection)
 		return 0
 
 	var/datum/signal/signal = new(command)
 	signal.data["tag"] = target
 	signal.data["sigtype"] = "command"
+	signal.data["user"] = user
 	radio_connection.post_signal(src, signal, RADIO_FROM_AIRALARM)
 
 	return 1
 
+/obj/machinery/airalarm/proc/get_mode_name(mode_value)
+	switch(mode_value)
+		if(AALARM_MODE_SCRUBBING)
+			return "Filtering"
+		if(AALARM_MODE_CONTAMINATED)
+			return "Contaminated"
+		if(AALARM_MODE_VENTING)
+			return "Draught"
+		if(AALARM_MODE_REFILL)
+			return "Refill"
+		if(AALARM_MODE_PANIC)
+			return "Panic Siphon"
+		if(AALARM_MODE_REPLACEMENT)
+			return "Cycle"
+		if(AALARM_MODE_SIPHON)
+			return "Siphon"
+		if(AALARM_MODE_OFF)
+			return "Off"
+		if(AALARM_MODE_FLOOD)
+			return "Flood"
+
 /obj/machinery/airalarm/proc/apply_mode()
 	var/area/A = get_area(src)
 	switch(mode)
@@ -451,7 +510,7 @@
 			for(var/device_id in A.air_scrub_names)
 				send_signal(device_id, list(
 					"power" = 1,
-					"set_filters" = list(/datum/gas/carbon_dioxide),
+					"set_filters" = list(/datum/gas/carbon_dioxide, /datum/gas/miasma),
 					"scrubbing" = 1,
 					"widenet" = 0,
 				))
@@ -467,6 +526,7 @@
 					"power" = 1,
 					"set_filters" = list(
 						/datum/gas/carbon_dioxide,
+						/datum/gas/miasma,
 						/datum/gas/plasma,
 						/datum/gas/water_vapor,
 						/datum/gas/hypernoblium,
@@ -503,7 +563,7 @@
 			for(var/device_id in A.air_scrub_names)
 				send_signal(device_id, list(
 					"power" = 1,
-					"set_filters" = list(/datum/gas/carbon_dioxide),
+					"set_filters" = list(/datum/gas/carbon_dioxide, /datum/gas/miasma),
 					"scrubbing" = 1,
 					"widenet" = 0,
 				))

code/modules/atmospherics/machinery/components/binary_devices/circulator.dm

@@ -145,6 +145,8 @@
 	return TRUE
 
 /obj/machinery/atmospherics/components/binary/circulator/screwdriver_act(mob/user, obj/item/I)
+	if(..())
+		return TRUE
 	panel_open = !panel_open
 	I.play_tool_sound(src)
 	to_chat(user, "<span class='notice'>You [panel_open?"open":"close"] the panel on [src].</span>")

code/modules/atmospherics/machinery/components/binary_devices/volume_pump.dm

@@ -131,6 +131,7 @@ Thus, the two variables affect pump operation are set in New():
 	switch(action)
 		if("power")
 			on = !on
+			message_admins("Pump, [src.name], turned [on ? "on" : "off"] by [ADMIN_LOOKUPFLW(usr)] at [ADMIN_COORDJMP(T)], [A]")
 			investigate_log("was turned [on ? "on" : "off"] by [key_name(usr)]", INVESTIGATE_ATMOS)
 			. = TRUE
 		if("rate")
@@ -185,3 +186,7 @@ Thus, the two variables affect pump operation are set in New():
 	if(. && on && is_operational())
 		to_chat(user, "<span class='warning'>You cannot unwrench [src], turn it off first!</span>")
 		return FALSE
+	else
+		investigate_log("Pump, [src.name], was unwrenched by [key_name(usr)] at [x], [y], [z], [A]", INVESTIGATE_ATMOS)
+		message_admins("Pump, [src.name], was unwrenched by [ADMIN_LOOKUPFLW(user)] at [A]")
+		return TRUE

code/modules/atmospherics/machinery/components/unary_devices/cryo.dm

@@ -294,7 +294,7 @@
 		user.visible_message("[user] places [I] in [src].", \
 							"<span class='notice'>You place [I] in [src].</span>")
 		var/reagentlist = pretty_string_from_reagent_list(I.reagents.reagent_list)
-		log_game("[key_name(user)] added an [I] to cyro containing [reagentlist]")
+		log_game("[key_name(user)] added an [I] to cryo containing [reagentlist]")
 		return
 	if(!on && !occupant && !state_open && (default_deconstruction_screwdriver(user, "pod-off", "pod-off", I)) \
 		|| default_change_direction_wrench(user, I) \

code/modules/atmospherics/machinery/components/unary_devices/thermomachine.dm

@@ -3,8 +3,9 @@
 	desc = "Heats or cools gas in connected pipes."
 	icon = 'icons/obj/atmospherics/components/thermomachine.dmi'
 	icon_state = "freezer"
-	var/icon_state_on = "cold_on"
-	var/icon_state_open = "cold_off"
+	var/icon_state_off = "freezer"
+	var/icon_state_on = "freezer_1"
+	var/icon_state_open = "freezer-o"
 	density = TRUE
 	max_integrity = 300
 	armor = list("melee" = 0, "bullet" = 0, "laser" = 0, "energy" = 100, "bomb" = 0, "bio" = 100, "rad" = 100, "fire" = 80, "acid" = 30)
@@ -37,7 +38,7 @@
 	else if(on && is_operational())
 		icon_state = icon_state_on
 	else
-		icon_state = initial(icon_state)
+		icon_state = icon_state_off
 
 /obj/machinery/atmospherics/components/unary/thermomachine/update_icon_nopipes()
 	cut_overlays()
@@ -72,7 +73,7 @@
 
 /obj/machinery/atmospherics/components/unary/thermomachine/attackby(obj/item/I, mob/user, params)
 	if(!on)
-		if(default_deconstruction_screwdriver(user, icon_state_open, initial(icon_state), I))
+		if(default_deconstruction_screwdriver(user, icon_state_open, icon_state_off, I))
 			return
 	if(default_change_direction_wrench(user, I))
 		return
@@ -157,6 +158,7 @@
 /obj/machinery/atmospherics/components/unary/thermomachine/freezer
 	name = "freezer"
 	icon_state = "freezer"
+	icon_state_off = "freezer"
 	icon_state_on = "freezer_1"
 	icon_state_open = "freezer-o"
 	max_temperature = T20C
@@ -182,6 +184,7 @@
 /obj/machinery/atmospherics/components/unary/thermomachine/heater
 	name = "heater"
 	icon_state = "heater"
+	icon_state_off = "heater"
 	icon_state_on = "heater_1"
 	icon_state_open = "heater-o"
 	max_temperature = 140 //actual maximum temperature is defined by RefreshParts()

code/modules/atmospherics/machinery/components/unary_devices/vent_pump.dm

@@ -337,6 +337,8 @@
 	if(!signal.data["tag"] || (signal.data["tag"] != id_tag) || (signal.data["sigtype"]!="command"))
 		return
 
+	var/mob/signal_sender = signal.data["user"]
+
 	if("purge" in signal.data)
 		pressure_checks &= ~EXT_BOUND
 		pump_direction = SIPHONING
@@ -352,7 +354,10 @@
 		on = !on
 
 	if("checks" in signal.data)
+		var/old_checks = pressure_checks
 		pressure_checks = text2num(signal.data["checks"])
+		if(pressure_checks != old_checks)
+			investigate_log(" pressure checks were set to [pressure_checks] by [key_name(signal_sender)]",INVESTIGATE_ATMOS)
 
 	if("checks_toggle" in signal.data)
 		pressure_checks = (pressure_checks?0:NO_BOUND)
@@ -361,10 +366,16 @@
 		pump_direction = text2num(signal.data["direction"])
 
 	if("set_internal_pressure" in signal.data)
+		var/old_pressure = internal_pressure_bound
 		internal_pressure_bound = CLAMP(text2num(signal.data["set_internal_pressure"]),0,ONE_ATMOSPHERE*50)
+		if(old_pressure != internal_pressure_bound)
+			investigate_log(" internal pressure was set to [internal_pressure_bound] by [key_name(signal_sender)]",INVESTIGATE_ATMOS)
 
 	if("set_external_pressure" in signal.data)
+		var/old_pressure = external_pressure_bound
 		external_pressure_bound = CLAMP(text2num(signal.data["set_external_pressure"]),0,ONE_ATMOSPHERE*50)
+		if(old_pressure != external_pressure_bound)
+			investigate_log(" external pressure was set to [external_pressure_bound] by [key_name(signal_sender)]",INVESTIGATE_ATMOS)
 
 	if("reset_external_pressure" in signal.data)
 		external_pressure_bound = ONE_ATMOSPHERE

code/modules/atmospherics/machinery/components/unary_devices/vent_scrubber.dm

@@ -17,7 +17,6 @@
 	var/scrubbing = SCRUBBING //0 = siphoning, 1 = scrubbing
 
 	var/filter_types = list(/datum/gas/carbon_dioxide)
-
 	var/volume_rate = 200
 	var/widenet = 0 //is this scrubber acting on the 3x3 area around it.
 	var/list/turf/adjacent_turfs = list()
@@ -43,6 +42,7 @@
 	..()
 	if(!id_tag)
 		id_tag = assign_uid_vents()
+
 	for(var/f in filter_types)
 		if(istext(f))
 			filter_types -= f
@@ -118,7 +118,7 @@
 /obj/machinery/atmospherics/components/unary/vent_scrubber/proc/broadcast_status()
 	if(!radio_connection)
 		return FALSE
-
+	
 	var/list/f_types = list()
 	for(var/path in GLOB.meta_gas_info)
 		var/list/gas = GLOB.meta_gas_info[path]
@@ -140,8 +140,8 @@
 	if(!A.air_scrub_names[id_tag])
 		name = "\improper [A.name] air scrubber #[A.air_scrub_names.len + 1]"
 		A.air_scrub_names[id_tag] = name
-	A.air_scrub_info[id_tag] = signal.data
 
+	A.air_scrub_info[id_tag] = signal.data
 	radio_connection.post_signal(src, signal, radio_filter_out)
 
 	return TRUE
@@ -171,7 +171,6 @@
 /obj/machinery/atmospherics/components/unary/vent_scrubber/proc/scrub(var/turf/tile)
 	if(!istype(tile))
 		return FALSE
-
 	var/datum/gas_mixture/environment = tile.return_air()
 	var/datum/gas_mixture/air_contents = airs[1]
 	var/list/env_gases = environment.gases
@@ -185,9 +184,11 @@
 
 			//Take a gas sample
 			var/datum/gas_mixture/removed = tile.remove_air(transfer_moles)
+
 			//Nothing left to remove from the tile
 			if(isnull(removed))
 				return FALSE
+
 			var/list/removed_gases = removed.gases
 
 			//Filter it
@@ -204,10 +205,9 @@
 
 			//Remix the resulting gases
 			air_contents.merge(filtered_out)
-
 			tile.assume_air(removed)
 			tile.air_update_turf()
-
+	
 	else //Just siphoning all air
 
 		var/transfer_moles = environment.total_moles()*(volume_rate/environment.volume)
@@ -221,7 +221,6 @@
 
 	return TRUE
 
-
 //There is no easy way for an object to be notified of changes to atmos can pass flags
 //	So we check every machinery process (2 seconds)
 /obj/machinery/atmospherics/components/unary/vent_scrubber/process()
@@ -230,17 +229,19 @@
 
 //we populate a list of turfs with nonatmos-blocked cardinal turfs AND
 //	diagonal turfs that can share atmos with *both* of the cardinal turfs
+
 /obj/machinery/atmospherics/components/unary/vent_scrubber/proc/check_turfs()
 	adjacent_turfs.Cut()
 	var/turf/T = get_turf(src)
 	if(istype(T))
 		adjacent_turfs = T.GetAtmosAdjacentTurfs(alldir = 1)
 
-
 /obj/machinery/atmospherics/components/unary/vent_scrubber/receive_signal(datum/signal/signal)
 	if(!is_operational() || !signal.data["tag"] || (signal.data["tag"] != id_tag) || (signal.data["sigtype"]!="command"))
 		return 0
 
+	var/mob/signal_sender = signal.data["user"]
+
 	if("power" in signal.data)
 		on = text2num(signal.data["power"])
 	if("power_toggle" in signal.data)
@@ -251,10 +252,13 @@
 	if("toggle_widenet" in signal.data)
 		widenet = !widenet
 
+	var/old_scrubbing = scrubbing
 	if("scrubbing" in signal.data)
 		scrubbing = text2num(signal.data["scrubbing"])
 	if("toggle_scrubbing" in signal.data)
 		scrubbing = !scrubbing
+	if(scrubbing != old_scrubbing)
+		investigate_log(" was toggled to [scrubbing ? "scrubbing" : "siphon"] mode by [key_name(signal_sender)]",INVESTIGATE_ATMOS)
 
 	if("toggle_filter" in signal.data)
 		filter_types ^= gas_id2path(signal.data["toggle_filter"])

code/modules/atmospherics/machinery/other/meter.dm

@@ -40,11 +40,15 @@
 	return ..()
 
 /obj/machinery/meter/proc/reattach_to_layer()
+	var/obj/machinery/atmospherics/candidate
 	for(var/obj/machinery/atmospherics/pipe/pipe in loc)
 		if(pipe.piping_layer == target_layer)
-			target = pipe
-			setAttachLayer(pipe.piping_layer)
-			break
+			candidate = pipe
+			if(pipe.level == 2)
+				break
+	if(candidate)
+		target = candidate
+		setAttachLayer(candidate.piping_layer)
 
 /obj/machinery/meter/proc/setAttachLayer(var/new_layer)
 	target_layer = new_layer
@@ -140,6 +144,5 @@
 //	why are you yelling?
 /obj/machinery/meter/turf
 
-/obj/machinery/meter/turf/Initialize()
-	. = ..()
+/obj/machinery/meter/turf/reattach_to_layer()
 	target = loc

code/modules/atmospherics/machinery/portable/canister.dm

@@ -50,6 +50,7 @@
 		"stimulum" = /obj/machinery/portable_atmospherics/canister/stimulum,
 		"pluoxium" = /obj/machinery/portable_atmospherics/canister/pluoxium,
 		"caution" = /obj/machinery/portable_atmospherics/canister,
+		"miasma" = /obj/machinery/portable_atmospherics/canister/miasma
 	)
 
 /obj/machinery/portable_atmospherics/canister/interact(mob/user)
@@ -137,6 +138,13 @@
 	gas_type = /datum/gas/water_vapor
 	filled = 1
 
+/obj/machinery/portable_atmospherics/canister/miasma
+	name = "miasma canister"
+	desc = "Miasma. Makes you wish your nose were blocked."
+	icon_state = "miasma"
+	gas_type = /datum/gas/miasma
+	filled = 1
+
 /obj/machinery/portable_atmospherics/canister/proc/get_time_left()
 	if(timing)
 		. = round(max(0, valve_timer - world.time) / 10, 1)

code/modules/atmospherics/machinery/portable/portable_atmospherics.dm

@@ -91,6 +91,7 @@
 	..()
 	if(holding)
 		to_chat(user, "<span class='notice'>\The [src] contains [holding]. Alt-click [src] to remove it.</span>")
+		to_chat(user, "<span class='notice'>Click [src] with another gas tank to hot swap [holding].</span>")
 
 /obj/machinery/portable_atmospherics/proc/replace_tank(mob/living/user, close_valve, obj/item/tank/new_tank)
 	if(holding)