I had more time available tonight so I decided to work on my fail-safe auto top-off (we'll call it FSAT so I don't have to keep typing that out ;o)
What do you think?
It is essentially the same design as the Sun Tea Jar design except with a very simple yet elegant twist to keep pressure in the reservior.
Ok, lets walk through the entire process.
To fill the container:
1. Turn the water valve to closed (so water doesn't leak into the display tank)
3. Get your bucket of water
2. Hook a powerhead or aqua-lifter to the end of the 5/8" tube, place the pump in the bucket and turn it on
3. Turn off pump when reservior is full
4. Turn water valve to open (to engage FSAT)
The trap in the 5/8" tube will create a pressure seal in the reservior.
When the water in the display tank gets lower than the other 5/8" tube it will break the pressure seal and allow the water to drip through the 1/4" tube. Once the water level is higher than the 5/8" tube in the tank it will create a pressure seal and stop the water flow.
This system is fail-safe *not* fail-proof. If the FSAT fails it will fail in the off position meaning your auto top-off will not work. It will never fail in the on position (meaning you flood your tank) assuming you keep the system air-tight and the reservoir container does not flex.
*Warning* if you make the trap small enough, or wait enough time I suppose the water will evaporate breaking the seal, but by that time the water will most likely have been put into the display tank, because everytime you fill the resevior you refill the trap.
What do you guys think? Any improvements? I think one could connect the 5/8" to a rodi unit so the reservior is always replenished. The only problem is if the rodi unit gets stuck on then your system will flood...