It does have a valve on it [img]http://www.**********.com/iBhtml/non-cgi/emoticons/smile.gif[/img] it actually made for reptiles and amphibians that need a wet and humid enviroment. its not necesarilly made for plants but I don't see why it can't be used for it. It also holds about a half a gallon.
Hm...Ill hook it up later when I get home now you got me wondering if it would work and if so for how long.
I think you may be thinking of some thing else DE but I will check it out since Ive been meaning to, #### it could save me some time watering