Approach to self filling dog bowl/pool

Hey guys,

Over here in Aus it gets pretty stinking hot and I've got two dogs who love to play in their water bowl (100L kids clam shell) and they'll routinely empty it in a single day which on 40°C days can be terminal.

So what I'm wanting to do is make a large concrete basin to fill with water, measure the level of the water and have it fill when it gets below a certain level.

I'm a little stuck on the best way to measure water. I've seen the ultrasonic method but because I'll have live animals going in and out and a water level that can slosh around I think that would be unreliable.

What I had in mind was simply having a fail off sort of connection where it will detect water on a sensor of some kind and when that sensor no longer detects water it will flip a solenoid connected to my water mains that will open up while it gets a high signal from hte arduino and close when it gets a low signal.

The only question the arduino needs to find out is "Is there water?" "yes/no" which should simply things and I'll just mount whatever sort of sensor I use to a point I want it to start filling from.

Does anyone have any suggestions?

Ever look inside a toilet tank?

My thought as well. What you're looking for is a ballcock. Much more reliable, cheaper and easier to implement.

vinceherman: Ever look inside a toilet tank?

Float sensor? The problem is getting one my dogs won't destroy... I wonder if I could make a small enough one with a magnet in the float and a reed switch and some PVC that i could embed into the concrete so my dogs can't get at it.

Stick the float and the reed switch into some 1" pvc pipe with a reed switch at the desired level and a magnet in a float of some kind. concrete the PVC into the wall of the bowl/pool so it's safe from Acts of Dog Then if the circuit is completed it's full if it's broken it needs topping up.

Great idea!

What about a simple gravity feeder, like the ones used in hamster cages? It's an upside down bottle with the spout just below the tray level. When the level goes below that, water gurgles out of the bottle and into the tray.

aarg: What about a simple gravity feeder, like the ones used in hamster cages? It's an upside down bottle with the spout just below the tray level. When the level goes below that, water gurgles out of the bottle and into the tray.

The reservoir has to be much larger than the thing you're filling for that to be practical and it sounds like the OP is building a big pool for the dogs, not just a water dish.

As you're building the pool from scratch, just build a small enclosed space next to it where you place your water inlet mechanism. Any other sensor you may want to build has the exact same protection problem.

How about a vertical toilet float valve inside a section of 4" sch 40 pvc with some holes drilled in it. You could use, for example, a 4" pvc flange fitting bolted to the bottom of the tank as a base and screw or slip the 4" pipe into it.

there are a lot of float valves out there - all mechanical - a float something like the toilet one mentioned above - have used them in the past several times to keep tank levels at the proper level - simple and goof proof - just put a screen around the float and valve to keep the dogs away from things - also look at a farm supply store for livestock trough valves - they should also have the mechanical float and might come already shielded from the livestock (cattle and horses are tough on things)