You know these things: Do they even work? Because i get the feeling if i put one of these into a bucket housing an MJ plant, it will not work.... Just a quick yes or no and the reason why please!
No too constant of a flow with no regulation can overwater, however if you are gone for awhile not a terrible idea...plus they are pretty small for a five gallon bucket kinda useless...
Not really. They just don't provide much water, they would be unlikely to cover the water needs of a good sized cannabis plant for more than a day or two. Those things are meant for houseplants and other slow growing plants, cannabis just grows too fast and needs too much water for something that size to really do anything. Now, if you really need something like this, another company makes a much larger version that uses inflatable bags meant for slow watering trees, that could do what you want.
Treegator is one of the brands that makes this sort of bag. The ones they make slow trickle out water over a period of about 9 hours to really soak the area. They are supposed to soak the ground well enough that you only need to refill them once a week. I've used them for transplanting trees, but not this particular application. There are other brands that release water faster or slower or have different water capacity, you really just need to look around. If you want to go DIY, you can get the same effect with a bucket and some parts for drip irrigation and have more control over exactly how much water your plant is getting.
The best thing I've seen/trying is a DIY set-up. Get a plastic tote, cut a garden sized hole near the bottom edge of the side, secure a water meter in that hole, then run a hose to the plant, and place a 2x4 under the opposite side of the tote to slant the water more towards the meter. There are meters that will measure out X # of gallons each watering, and you can set them up to water that much every 24, 48 or 72 hours, they also will not differ with pressure, or lack there of by using gravity. It is GREAT if you have outdoor plants and your going away, or if you are a guerrilla grower such as myself because the meter uses battery power. Next year I'm gunna make a few 50-gallon totes like this to water some guerrilla plants that I won't be able to get to often.
