When adjusting the setting of the Plant Booster device for the first time, how do you know what weight it should be set for?
It is very important to water the container plant manually by hand first to establish the properly watered weight. For hanging baskets, water the basket until it drips and then leave it to hang until the dripping stops. This may take some time, perhaps a few hours, and it depends on how well draining the soil is that has been used for the basket, as well as the ability for excess water to drain out. Make sure that your basket can drain properly.
At this point the soil in the container is still moist, but not overly wet.
Importantly, all the soil will still be moist, and not just a surface layer.
At this point, when the basket is no longer dripping, adjust the wingnut until it just does not drip water in. Any evaporation of water from the basket now will result in a weight loss, and thus cause te device to allow water in to re-establish the set weight.
If you adjust the Plant Booster device too soon (before it has completely stopped dripping), the device will from that point on work to maintain that weight, including the dripping.
If you have a dripping basket, just loosen the wingnut a quarter turn, and leave it to settle down for a day or so. If it is still dripping, loosen the wingnut another quarter turn, and so on. At some point you will find the right setting.