Follow these steps and you won't need to go out and spend £15 on a reptile dripper that does the same thing.
1. Get yourself an empty water bottle.
2. Cut the top of, to make the opening bigger.
3. Get yourself a pin, i suggest you get a lighter/match and warm the end of the pin, this will make it a whole lot easier to make a hole in the bottle.
4. Once you have got the pin warmed up make a small hole in the bottem of the bottle.
5.I t is finished, just fill it with water and place it on top of your viv.