Cheap way to ph up and down

I posted this in the Newbie section, but thought it would be good here too.

I recently was playing around with ways to move PH up and down and noticed two inexpensive ways.

Seltzer water (low PH) around 4.0 - 4.5
Purified Supermarket water (high PH) 7.5 - 8.5

I let the seltzer water sit out for a day without the cap on so it would go flat.

Anyway, I had a Guana mixture that was 8.5 and i lowered it to 6.5 by mixing in some flat seltzer.

I also got the seltzer up to 7 with the purified water,

I did these experiments with a digital PH meter that was calibrated right before I started so I know the readings were correct.

Hope this helps

Thanks alot.. i bought some mg organic choice and ph was high so i used your method and got it to were i need it... thanks alot

bog wood in ur water to raise ph

are you aware of how cheap actual PH up and down is and how far it goes? i spent £4 on a small bottle, that bottle lasted me 10 months.

apple cider vinegar and baking soda