in which / whereby

20:12 Mar 19, 2013 

I would use method over form. You might consider using a 'technique of' or 'approach to' hydroponic farming.

19:22 Mar 19, 2013 

yes.

18:27 Mar 19, 2013 

would in this specifc instance be quite wrong, as it is not in all cases a synonym for 'in which'; in point of fact, the synonym you could use here would in fact be simply 'where' — or the more formal 'wherein'.

As a sort of rule-of-thumb guide, the 'by' in both 'whereby' and 'thereby' conveys the sort of idea of 'by means of which' — "The trick whereby he was able to embezzle the money...".

Here, in your text, you can see that there is no causal element whatsoever, and hence the term would be out of place.

18:10 Mar 19, 2013 

Thank you Nancy.
Would you then also put a comma at the end?

....setups, in which the grow tray is laid down on top of the hydroponic channel, have...