The Ultrasonic tank depth RTC alarm water tank refilll

The tank wont be taller than a meter.(for now)

The code should stop the valve when the ultrasonic sensor reaches the full mark. (this way I can scale the system)
Hello! Im new to electronics but have a good sense of what arduino can do.. I need help getting it done.

Project summary: once a day the ultrasound will calculate the amount of water missing from the tank and open a 24vac water valve.

Parts list:
Arduino micro
tiny RTC
Ultrasonic US-020
6v relay
tip 122
24v ac valve. (with 24vac transformer)
resistors (1k, 2.2k, 4.7k)
diode in4004
and a 2n2222 transistor
an7806 voltage regulator (to power the arduino through the 24vac transformer)

Please feel free to discard and or add stuff to the list.

THANK YOU!

Ps:
the tank will be pumping water twice a day through a "APC Power Saving Surge Protector With LCD Timer"hooked to water pumps.
if powering the arduino thought the voltage regulator is "imposible" then i got the 9vbattery plug handy)
the "full" mark should be 15 to 20cm to keep the sensor clear of any water vapors and or spills.
I need to know what goes where on the arduino micro then I can ask for help with any specific code errors I might have.

Adafruit forum link http://forums.adafruit.com/viewtopic.php?f=25&t=53556

US-020 http://i01.i.aliimg.com/wsphoto/v0/6283 ... e-4PIN.jpg

Tiny rtc http://www.elecrow.com/wiki/images/2/23 ... rdware.jpg

Arduino micro http://arduino.cc/en/uploads/Main/Ardui ... inout2.png

Please help me.

PD: adafruit locked my post; they dont love open source.

How about providing some dimensions for the tank before asking for help.