diff --git a/code/datums/components/plumbing/_plumbing.dm b/code/datums/components/plumbing/_plumbing.dm
index e1333ebc3f4..3af63f290f8 100644
--- a/code/datums/components/plumbing/_plumbing.dm
+++ b/code/datums/components/plumbing/_plumbing.dm
@@ -101,9 +101,14 @@
 		var/datum/component/plumbing/supplier = A
 		if(supplier.can_give(amount, reagent, net))
 			valid_suppliers += supplier
+	// Need to ask for each in turn very carefully, making sure we get the total volume. This is to avoid a division that would always round down and become 0
+	var/targetVolume = reagents.total_volume + amount
+	var/suppliersLeft = valid_suppliers.len
 	for(var/A in valid_suppliers)
 		var/datum/component/plumbing/give = A
-		give.transfer_to(src, amount / valid_suppliers.len, reagent, net)
+		var/currentRequest = (targetVolume - reagents.total_volume) / suppliersLeft
+		give.transfer_to(src, currentRequest, reagent, net)
+		suppliersLeft--
 
 ///returns TRUE when they can give the specified amount and reagent. called by process request
 /datum/component/plumbing/proc/can_give(amount, reagent, datum/ductnet/net)
diff --git a/code/datums/components/plumbing/reaction_chamber.dm b/code/datums/components/plumbing/reaction_chamber.dm
index 39769190360..2fd837d229d 100644
--- a/code/datums/components/plumbing/reaction_chamber.dm
+++ b/code/datums/components/plumbing/reaction_chamber.dm
@@ -23,7 +23,7 @@
 		for(var/datum/reagent/containg_reagent as anything in reagents.reagent_list)
 			if(required_reagent == containg_reagent.type)
 				has_reagent = TRUE
-				if(containg_reagent.volume < chamber.required_reagents[required_reagent])
+				if(containg_reagent.volume + CHEMICAL_QUANTISATION_LEVEL < chamber.required_reagents[required_reagent])
 					process_request(min(chamber.required_reagents[required_reagent] - containg_reagent.volume, MACHINE_REAGENT_TRANSFER) , required_reagent, dir)
 					return
 		if(!has_reagent)
diff --git a/code/modules/plumbing/plumbers/plumbing_buffer.dm b/code/modules/plumbing/plumbers/plumbing_buffer.dm
index 25dadcfb2fb..6c7a7c33ed7 100644
--- a/code/modules/plumbing/plumbers/plumbing_buffer.dm
+++ b/code/modules/plumbing/plumbers/plumbing_buffer.dm
@@ -31,11 +31,11 @@
 /obj/machinery/plumbing/buffer/proc/on_reagent_change()
 	if(!buffer_net)
 		return
-	if(reagents.total_volume >= activation_volume && mode == UNREADY)
+	if(reagents.total_volume + CHEMICAL_QUANTISATION_LEVEL >= activation_volume && mode == UNREADY)
 		mode = IDLE
 		buffer_net.check_active()
 
-	else if(reagents.total_volume < activation_volume && mode != UNREADY)
+	else if(reagents.total_volume + CHEMICAL_QUANTISATION_LEVEL < activation_volume && mode != UNREADY)
 		mode = UNREADY
 		buffer_net.check_active()