water quality in pond


I've got 2 valves I can control with Arduino to water my garden or actually fill up my pond but i'd like to know what you'd recommand to test and monitor the water quality.

Thank you

There are several things you can measure wrt water quality but some are expensive (I mean really expensive) The cheaper part includes: - temperature - watertight DS18B20 is an excellent sensor for that - with LCD and a LDR you can measure first order transparency of the water - with a colour LCD and a colour detector you can make a sort of spectrum analyser to see deviations of some reference spectrum. (google liquid spectrum analyser arduino) - you can measure the conductivity of the water

more expensive is a PH measurement, e.g. see - https://www.atlas-scientific.com/ - They have a lot of cool stuf

almost undoable without a serious lab is measure e.g. nutricients

This should get you started

I am only just learning programming, EC Electron-Conductivity is an accurate way of measuring resistance or lack thereof from a reference voltage. PH is a scale that determine whether a substance is Acidic, Neutral, or Alkaline.

Salt is a conductor of electron flow, whereas Alkaline is a resistance of electron flow.

The oldest method is to test the flow/resistance along a neutral path (Horse Hair) between two probes (stainless steel) Hair is a neutral organic substance, which is susceptible to decay by salt or alkalinity. Horse/Donkey/Zebra/Lion hair is coarser/stronger than human hair, so degradation takes longer, Horse/Donkey hair is easier to obtain too :grin: 5mm lengths should be enough.

One probe is connected to Vcc, and the other to GND. The probe is inserted in a solution (Water) with neutral PH, the voltage obtained is your reference voltage. If the Voltage is higher than ref, the solution is acidic, if the voltage is lower than ref the solution is alkaline. Ref = Reference

I hope this helps in some way.

P.S. Hair is placed between the probes as it naturally absorbs salts, metals, etc. and is easier to replace, and cheaper to build.

Now I know why some brilliant chemists are bold ;)

More seriously, very interesting !

For measurements, you can connect the + side of a sensor to an output pin of the Arduino and only when the pin is made high a measurement can be made. This uses less energy and prevents electrolysis and possibly wear of the donkey hair.

WOW! Guys, a tutorial on how to do this exactly would be super cool!

You hold the lion, I'll pull the hair!


Paul_KD7HB: You hold the lion, I'll pull the hair!


then we run.and all I have to do is run one step faster than you.

check what is offered and recomended for fish tanks.
PH does not change for no reason. you might need to just test for somethings weekly. others continuously.