Shaders no lag with waves

local RunService = game:GetService("RunService")
local Workspace = game:GetService("Workspace")
local Players = game:GetService("Players")
local Lighting = game:GetService("Lighting")
local Camera = Workspace.CurrentCamera
local LocalPlayer = Players.LocalPlayer
local Terrain = Workspace:FindFirstChildOfClass("Terrain") or Instance.new("Terrain",Workspace)

getgenv().GI_SYSTEM = getgenv().GI_SYSTEM or {}
local GI = getgenv().GI_SYSTEM

for _,v in pairs(Lighting:GetChildren()) do
	if v:IsA("Sky") then v:Destroy() end
end

Lighting.Technology = Enum.Technology.Unified
Lighting.Ambient = Color3.fromRGB(65,61,86)
Lighting.Brightness = 3.6
Lighting.EnvironmentDiffuseScale = 0.1
Lighting.EnvironmentSpecularScale = 1
Lighting.GlobalShadows = true
Lighting.OutdoorAmbient = Color3.fromRGB(160,160,160)
Lighting.ShadowSoftness = 0.5
Lighting.GeographicLatitude = 41.733
Lighting.ExposureCompensation = 0.2
Lighting.FogColor = Color3.fromRGB(192,192,192)
Lighting.FogEnd = 100000
Lighting.ClockTime = 6.5

Terrain.WaterColor = Color3.fromRGB(12,81,89)
Terrain.WaterReflectance = 1
Terrain.WaterTransparency = 0.11
Terrain.WaterWaveSize = 0.45
Terrain.WaterWaveSpeed = 25

local sunrays = Instance.new("SunRaysEffect", Lighting)
sunrays.Intensity = 0.03
sunrays.Spread = 0.128

local atmosphere = Instance.new("Atmosphere", Lighting)
atmosphere.Density = 0.3
atmosphere.Decay = Color3.fromRGB(199,174,164)
atmosphere.Color = Color3.fromRGB(125,113,110)
atmosphere.Glare = 0.67
atmosphere.Haze = 0

local dof = Instance.new("DepthOfFieldEffect", Lighting)
dof.FarIntensity = 0.7
dof.FocusDistance = 0.05
dof.InFocusRadius = 50

local clouds = Instance.new("Clouds", Lighting)
clouds.Cover = 0.6
clouds.Density = 0.5
clouds.Color = Color3.fromRGB(225,246,217)

local sky = Instance.new("Sky")
sky.SkyboxBk = "rbxassetid://1618912481"
sky.SkyboxFt = "rbxassetid://1618913244"
sky.SkyboxLf = "rbxassetid://1618912849"
sky.SkyboxRt = "rbxassetid://1618911568"
sky.SkyboxUp = "rbxassetid://1618913654"
sky.SkyboxDn = "rbxassetid://1618913943"
sky.Parent = Lighting

spawn(function()
	while true do
		Terrain.WaterWaveSpeed = 25 + math.sin(tick()*0.5)*15
		Terrain.WaterWaveSize = 0.45 + math.sin(tick()*0.3)*0.2
		task.wait(0.1)
	end
end)

RunService.RenderStepped:Connect(function()
	if Workspace:FindFirstChildOfClass("Terrain") then
		clouds.Parent = Lighting
	else
		clouds.Parent = nil
	end
end)