Malkon, you may like to use ...
Published by Veronika Vasilev
Malkon, you may like to use Fulcrum - water Sample Testing app: This can collect record water samples for testing around agriculture, aquaculture, well water, livestock, pesticides, or petrochemicals.http://www.fulcrumapp.com/apps/water-sample-testing-form/
Not sure if thats available for free. But good to check.
Also explore Water Quality Reporter app if possible.