I started my dripper irrigation a month ago and this comes from feedback in the CR4 engineering forum from user tcmtech. It is much simpler than my idea and refills automatically from any rainshower., This instructable hopefully shows very clearly that it works. I use a glass pot lid as the float. The handle has been removed in the middle and the plastic tube inserted through the hole. The hole to let out steam is where the water comes in. In the "real thing" the inlet water would have a filter outside and the hole could be either raised and lowered or made smaller to regulated the drip speed. The float would not be a glass pot lid in real life and it might have sealed balast or floats but it might have a similar center of gravity, etc.