What about citric acid? Iv read its ok to use & its used in winemaking to lower ph. You can pic it up at Wilkos for dirt cheap http://www.wilko.com/home-brewing/wilko-citric-acid-50g/invt/0022652
Here's a good thread from another forum,but well worth a read https://www.icmag.com/ic/showthread.php?t=191399
Good call Redeye! seems to be a nice alternative and can't argue with the science!