C# MF threading problem

using System;
using System.Threading;
using Microsoft.SPOT;
using Microsoft.SPOT.Hardware;
using SecretLabs.NETMF.Hardware;
using SecretLabs.NETMF.Hardware.Netduino;

namespace hydroponic
{
    public class Program
    {
        public const int SecondMs = 1000;
        public const int MinuteMs = 60 * SecondMs;
        public const int HourMs = 60 * MinuteMs;
        public const int DayMs = 24 * HourMs;
        public const int WeekMs = 7 * DayMs;

        static bool method_state_6, method_state_7;


        static InputPort phcontroller = new InputPort(Pins.GPIO_PIN_D0, false, Port.ResistorMode.Disabled);  //Relay input
        static InputPort nutcontroller = new InputPort(Pins.GPIO_PIN_D1, false, Port.ResistorMode.Disabled);  //Relay input
        static OutputPort ph = new OutputPort(Pins.GPIO_PIN_D2, true);  //optical Relay output (reversed on/off as they are optical)
        static OutputPort b = new OutputPort(Pins.GPIO_PIN_D3, true);  //optical Relay output (reversed on/off as they are optical)
        static OutputPort a = new OutputPort(Pins.GPIO_PIN_D4, true);  //optical Relay output (reversed on/off as they are optical)
        static OutputPort drain = new OutputPort(Pins.GPIO_PIN_D5, true);  //optical Relay output (reversed on/off as they are optical)
        static OutputPort solenoid = new OutputPort(Pins.GPIO_PIN_D6, true);  //optical Relay output (reversed on/off as they are optical)
        static OutputPort controller = new OutputPort(Pins.GPIO_PIN_D7, true);  //optical Relay output (reversed on/off as they are optical)
        static OutputPort led = new OutputPort(Pins.GPIO_PIN_D11, true);  //optical Relay output (reversed on/off as they are optical)


        
        public static void Main()
        {

            try
            {
                Thread led_proc = new Thread(new ThreadStart(turn_led));
                led_proc.Start();
                while (true)
                {

                    method_state_6 = method_state_7 = true;
                    
                       
                    Method_1();
                    call2_5();
                    call6_8();
                    Method_10();
                    Thread.Sleep(10000);

                }
            }
            catch
            {
                //Something has gone wrong; reset to a safe condition
            }
        }


        static void turn_led() //turn led light on for 12 hrs and off for 12hrs in loop.
        {
            while (true)
            {
                led.Write(false);
                Thread.Sleep(HourMs * 12);
                led.Write(true);
                Thread.Sleep(HourMs * 12);
            }
        }

        public static void call2_5()
        {
            Thread t2 = new Thread(new ThreadStart(Method_2));
            t2.Start();
            Thread t3 = new Thread(new ThreadStart(Method_3));
            t3.Start();
            Thread t4 = new Thread(new ThreadStart(Method_4));
            t4.Start();
            Thread t5 = new Thread(new ThreadStart(Method_5));
            t5.Start();
            #region Wait for finishing 2-5 methods
            t2.Join();
            t3.Join();
            t4.Join();
            t5.Join();
            #endregion
        }
        static void call6_8()
        {
            Thread t6 = new Thread(new ThreadStart(Method_6));
            t6.Start();
            Thread t7 = new Thread(new ThreadStart(Method_7));
            t7.Start();
            Thread t9 = new Thread(new ThreadStart(Method_9));
            t9.Start();

            // wait for Method_9 finishing
            t9.Join();
            method_state_6 = method_state_7 = false;
        }
        public static void Method_1() //Drains the System (water nutrient mix)
        {
            drain.Write(false);
            Thread.Sleep(16 * MinuteMs);
            drain.Write(true);
        }
        public static void Method_2() //Fills the System with Water
        {
            solenoid.Write(false);
            Thread.Sleep(16 * MinuteMs);
            solenoid.Write(true);
        }
        public static void Method_3() //Doses the system with nutrient a
        {
            a.Write(false);
            Thread.Sleep(182 * SecondMs);
            a.Write(true);
        }
        public static void Method_4() //Doses the system with nutrient b
        {
            b.Write(false);
            Thread.Sleep(100 * SecondMs);
            b.Write(true);
        }
        public static void Method_5() //Doses the system with PH down
        {
            ph.Write(false);
            Thread.Sleep(5 * SecondMs);
            ph.Write(true);
        }
        public static void Method_6() // reads the PH controller realy contactcts if opend/closed when closed it does this
        {
            while (phcontroller.Read() == true && method_state_6 == true)
            {
                ph.Write(false);
                Thread.Sleep(1 * SecondMs);
                ph.Write(true);
                Thread.Sleep(5 * MinuteMs);
            }
        }
        public static void Method_7() // reads the nutrient controller realy contactcts if opend/closed when closed it does this
        {
            while (nutcontroller.Read() == true && method_state_7 == true)
            {
                a.Write(false);
                Thread.Sleep(5454);
                a.Write(true);
                b.Write(false);
                Thread.Sleep(3000);
                b.Write(true);
                Thread.Sleep(5 * MinuteMs);
            }
        }
        public static void Method_9() //Tops up the system with a little water each day, then in 14 days moves on to Method_10
        {
            controller.Write(false); //turns on the two controllers PH and Nutrients
            for (int i = 0; i < 14; i++)
            {
                Thread.Sleep(1 * DayMs);
                solenoid.Write(false);
                Thread.Sleep(20 * SecondMs);
                solenoid.Write(true);

            }
            controller.Write(true);
        }
        public static void Method_10() // Flushes the system, drains then fill water.
        {
            drain.Write(false);
            Thread.Sleep(16 * MinuteMs);
            drain.Write(true);
            solenoid.Write(false);
            Thread.Sleep(16 * MinuteMs);
            solenoid.Write(true);
            Thread.Sleep(1 * MinuteMs);
          
        }
                         //Whole thing loops
    }
}