while true do
    tanks = peripheral.call("right","tanks")
    lava = 0
    for i,v in pairs(tanks) do
        if v.name == "minecraft:lava" then
            lava = lava + v.amount
        end
    end
    
    if lava > 300 then
        peripheral.call("right","pushFluid","left",lava - 300)
    end
end