I am looking for a small simple switch. But it has certain restrictions because I want to use it for salt water aquarium and copper exposure is lethal to some fauna, as well as some plastics.
Looking around the internet i found floating switches, optical switches, rod inducting switches, a few diy projects switches i.e. a Sonar switch- very promising just with salt.. well salt accumulates in every place possible under the hood.
I might go with the sonar and a small arduino or attiny…
but I am wondering if it is possible to use a single wire to detect resistance change? or something clever like that. I only want to detect if the aquarium is about to overflow and shutdown pumps in case off emergency- so minimum copper exposure wont kill anything but flooding my wooden floor.. well the wife will kill me..
My aquarium (and most other Marine hobbyists will have these spec ranges)(only advanced people will go over or under these for other specific reasons)
- Temp 22~26 Celsius (ME: 24oC)
- Salinity 1.022 ~ 1.026 (ME: 1.026) (Specific Gravity)
But I would like to assume this works on Clean water too( as in Reverse Osmosis with no minerals or salt) The distance would be max 1 cm apart- no need to measure the entire tank.