autotimer turn on/off based on mechanical time.
when you plug timer to power, you need to adjust what is current time.
then normally there is be small switches to control to ON. so when ON, then power flow through, then ON your light.
this is what we been using for co2 tank. everything is automatic

you only need to refill water and sit back relax.
Added on May 9, 2012, 12:50 pmriccia same as moss, co2 is optional for them, if you put then they will grow nicely, if you never put then they will still survive, AS LONG AS you got correct light power.
if you want to know more about light power which suitable for your aquarium, please refer to my wordpress blog.
mini fissiden need cold water, if you water is more than 29C, dont take the risk, as they are not cheap
I am thinking, how long does the ADA remain in good condition in the water? Do you ever change the soil? Once you have setup your planted tank, is it possible to remove the water and soil to rescape using the existing plants?
I want to buy plants to setup with my 2.5ft tank, but I don't want to do any nice scaping yet, just want to take care and grow them.