darp...

for the worst case scenario...

take a two liter soda bottle.
Drill the smallest hole you can find in a drill bit right thru the cap.
Fill the soda jug.
Turn upside down.
Let the water drip into a cup. DO it now so you can adjust the drip.

See how much drips in a day.

Try to adjust the size of the hole to where it is dripping at about the quantity where you normally water you plants.

Say a half gallon every 2 days....make the hole so it drips about the same. Do it now so you can measure the accuracy before you leave.

Place the bottle upside down so the drip hole is clear and uncluttered and GO ON VACATION.

If you like, buy one of those X10 cams for 39.00 thats transmits a wireless signal to your PC. Put it on your plants and view your grow while you are gone.

Have a friendin mine, whereas if disaster should strike, you can call him / her and for emergency only, save your plants.

I hope some of these ideas are beneficial.

I know I could never leave lights on 24/0 or even 18/6 for 6 days and not have to water. I guess a lot depends on your soil, but I have to water every 2 days and now the big girls are drinking 1/2 gal a day.

Good luck and HAPPY GROWING!