''We tested three times - before, during and after a crop - and found very little difference in water quality between the two farms,'' he said.
''The testing provided an overview of what was in the water and allowed us to speculate on some of the reasons for the results.''
McCrostie said he was able to take it from there and begin to apply his local knowledge with a view to improving soil health.
''The first thing to note was that all the water on both properties was within the standards for New Zealand drinking water,'' he said.
''We also noted that the soil changed as it attempted to respond to organic pressure with changes in the chemical reactions taking place.''
In effect, the soil was compensating for the punishment it was being subjected to, he said.
From there it was a matter of looking at the results and working back from that point.
''Our approach is to focus on soil health and microbial action which has meant focusing on things such as the sources of carbon being applied to the land.''
The results of the testing and follow-up had reinforced his confidence in his farming system and on-farm practices and the results had been reflected in improved animal health.
''It's been a challenge to expose our results and approach to other farmers.
''When I first presented them to the community there was not a lot of interest.''
An issue was it was often difficult to achieve a handover of knowledge when faced with the individualism of many farmers.
''The arrival of dairying has seen many changes in the district and on occasions I feel like a bit of a stranger in my own area.''
McCrostie's property is close to the Waituna wetlands which are the focus of a strategy and action plan to preserve the Waituna Lagoon and he has been involved in this process on behalf of the local community.
''It's a challenging time for locals and already the focus on our local environment has impacted on things such as land values,'' he said.
''Hopefully, it is something that we can work through and achieve a result that supports environmental objectives and our community.''