After playing with these things, I've discovered that they don't do exactly what I thought, but are definitely cool. They have bluetooth so I was hoping that I could just walk along the pond and check the temps on my ph. Unless I'm missing something, I've found that you have to retrieve them, press a button, and essentially collect a history of water temps. That's OK even if it is not what I had envisioned. I'm just glad I figured it out before the structure sank that I had one mounted on. Now I'll just attach each one to a weight/rope and collect data whenever I need to.
