Very much a newbie question:

I see a lot of talk of monitoring & measuring DO & temperature levels but I can't find tools to measure those.

In a perfect world sensors could be dropped or staked at predefined depths then report back via WiFi with alerts if thresholds are breached. Yup, I'm a nerd.

Any such items to recommend & maybe share a link?

1.25 Acre Pond 8 Feet Deep

Some Koi & Large Mouth Bass