I'd like to keep plants watered during a trip, with about 2l of water per 24 hours. I tried making a siphon with a screw-adjusted clamp to let water out at a controlled pace, but while it originally kept the flow at one drop every two seconds, over the next ten hours it had slowed down to one drop every ten seconds, and after a five more it had stopped entirely. The water is coming from a 10l tank that's higher than the siphon's end, so why does the flow die down over time?
And of course, are there any other reliable ways to keep the plants watered over the weekend? I've heard you could just plop a bottle upside down in the dirt, but does that really work that safely? The pot has holes at the bottom of it, so unless the water is absolutely certain to seep out slowly enough I wouldn't dare to leave it unattended for a long time like that.