Lower pH?

[Aienu]

I have a natural high pH (alkaline/basic) in my tap water (8.4). Anyone have any ways of lowering this without using chemicals?

 

[Alien Anna]

I put loads of bogwood in my tank and I pre-filter water change water through peat. The important thing is to let the peat-filtered water stand for a bit to let all the CO2 bubbles escape as otherwise it causes pH swings.

I also have CO2 but that doesn't have a huge effect on pH because my water is so hard.

By these means I've got my pH down to 6.8. The important thing is to go really slowly - 10-15% water changes with peat-filtered water per week is good.