how to a block slowly extend up every 1 second for 10 seconds?

Explorer Window Info https://cdn.discordapp.com/attachments/754079651147677787/851118306181382204/unknown.png

Im trying to make a custom SCP for my scp game but i cant get it to work, i just get this error: 10:54:44.593 Workspace.SCP-967.AffectedObjects.SCP.Chair.Seat.Script:16: invalid argument #2 (Vector3 expected, got number) - Server - Script:16

also i get this after but i dont know what it means...: 10:54:44.593 Stack Begin - Studio 10:54:44.594 Script 'Workspace.SCP-967.AffectedObjects.SCP.Chair.Seat.Script', Line 16 - Studio - Script:16 10:54:44.594 Stack End - Studio

--Property Of YK Studios--
local Seat =  script.Parent
local AffectedObjectsFolder = Seat.Parent.Parent.Parent
local MistEmitter = AffectedObjectsFolder.Mist.ResizeMe.Emitter
local UnknownLiquid = AffectedObjectsFolder.GreenGOO

Seat:GetPropertyChangedSignal("Occupant"):Connect(function()
    if Seat.Occupant ~= nil then
        local Char = Seat.Occupant.Parent
        Char["HumanoidRootPart"].Anchored = true
        MistEmitter.Enabled = true
        AffectedObjectsFolder.ContainmentRoomGlass.Material = "Plastic"
        wait(11)
        for count = 1, 10 do
            wait(1)
            UnknownLiquid.size = Vector3.new(UnknownLiquid.size + 0,1,0)
            print("Changed Size, New Value: "+ UnknownLiquid.size)
        end
    end
end)