I made a medium strong soil mix and never added any fertilisers, only used an organic mix of fulvic+amino acids and vitamin complex. Applied once foliar + in soil during early/mid flowering.
The idea was that Thais and sativas in general don't require strong nutrient doses, are actually better with less. It showed in mid flowering with early yellowing(some growers prefer this) so I applied a light mix to boost their environmental response(was a very bad summer). Also I think the soil should have been more airy with good drainage, sativas and overly damp soil don't get along well, but what can you do with 20 days of rain per month.
Key for outdoors guerrilla is to keep it simple(good soil, plant support, safe place), find out the plant's basic needs, the sun(or lack of) will do the rest.