One thing I couldn't find an answer on is whether these sensors can come in contact with actual water, instead of only the water vapor in the air.
Does anyone have experience with these type of sensors in relation to hydroponics? What type of sensor do I need? Is there a better way of building a feedback-based watering system?
Attached is a datasheet for a water level detector that works using two metal probes very close together . This can be made using
a cork with two small holes punched through it or some material that you poke the probes through and hot glue them to the material at the holes. They should be as close together as you can get without actually touching (1 to 3 mm).
Look at figure 3 & 4 on page 5 for example circuits. I have used this chip and it works well. There are a bunch of example circuits on those pages.
I... What you want to see the level of water if its a Hydroponic system? sorry but Im working in almost the same and I think that what you need is change the water or looking the conductivity and pH, but not the level. In any case if is a full hydroponic system (100% water) what you have to use is a Water level sensor, and in the other hand, if you are ussing a mix of Hydroponic system (sand + water) you can use the moisture sensor that the guys give you... Send me an email if you need help or a PM!