Out of interest, around this time last year I had some samples from my yards tested by Logan Lab's in the US. It actually wasn't that expensive to ship and have the tests performed. I had pH levels of 8.0 & 7.7 at a 10cm depth. Ideally couch should have a pH of 6.5 ish.

IMO, there really isn't much you can do change your pH in a short period of time. It takes years to change soil chemistry, just based purely on the shear volume of the soil. That being said there are other factors which are just as important as pH and attempting to change the pH purely to get a specific number can be detrimental to other aspects of the soil.

I have attached my soil report for interest sake.

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