Let's look at these carbon sources in detail:
a) Pressurized CO2 tanks
When people talk about high tech setups, they are referring to the use of a pressurized CO2 tank. You can find Mudraker's awesome step by step guide on building a pressurized CO2 system using this link:
http://www.aquariumadvice.com/forums/f24/how-to-set-up-a-co2-system-137982.html
Briefly, the high tech pressurized CO2 hardware includes:
1) tank cylinder - houses the CO2 in liquid form
2) regulator - control system that releases the gas from the cylinder
3) high pressure gauge - tells you how much CO2 is remaining inside the tank cylinder
4) low pressure gauge - tells you the working pressure is inside the regulator chamber
5) bubble counter - shows you the amount of CO2 gas entering your tank in units of bubbles per second
6) needle valve - precisely regulates the number of gas bubbles per second
7) check valve - prevents water from entering into and destroying your regulator
8) solenoid - electronic device that turns your CO2 regulator on and off
9) timer - automatically activates your solenoid on and off at your specified times
10) CO2 diffuser or reactor - allows the CO2 gas to dissolve quickly and efficiently into the water
11) CO2 resistant tubing - special tubing resistant to CO2 acid damage, connects the bubble counter to the diffuser/reactor.
You can buy each piece of hardware from amazon dot com, with higher end models available from greenleaf aquariums dot com. Expect to spend a total of at least $200 for the most basic setup PLUS $20 to $60 per year in CO2 refill costs. Here is an approximate breakdown of how much each part costs:
1) CO2 tank cylinder - $65 to $100 for 5 pound and 10 pound models respectively. Larger cylinders needs to be refilled less often.
2) regulator kit with solenoid - $90 to $500
3) bubble counter - $15 to $25
4) check valve - $10
5) CO2 resistant tubing - $10
6) timer - $5 to $20
7) CO2 refill - $20 to $30 per refill for 5 to 10 pound cylinders. Refill frequency will depend on your aquarium size, cylinder size, and number of hours the solenoid is turned on. On my 125 gallon tank, a 10 pound cylinder will last about 6 months before requiring a refill, with the solenoid turned on for 8 hours a day.
8) CO2 diffuser or reactor - $5 to $40