If you can't buffer with the soil itself, I would think proper pH down, aka phosphoric acid, would be the best bet for correcting water. But, I'm a DWC guy who fed his backyard plants with pH 9 hose water.
sorry for the delay in posting...
the final dried and trimmed yield is just under 40g not too bad for a first grow of 4 plants i think.
the smoke is very good too. good enough to rival anything else around here and that includes some well known varieties!