regarding brunning peat moss - see this thread
Seems to have done the trick for the OP with regards to pH and growing plants. No report on water softening.
I have not tried it but am very interested to test it in my next small tank setup.
For pH, I have experimented on Seachem discus buffer, API Ph Down and Pool acid (sodium biphophonates), HCL and Indian almond leaves, all with Perth tap water. Didnt find indian almond leaves to be effective at all in lowering pH. Pool acid and HCl were unpredictable and if you're not careful with measuring parameters, you can get some wild swings. Wouldnt recommend using them unless you can keep a close eye for these swings. Having said that, I have bred some pretty finicky acidic loving fish with em.
Agree with Ronny that Seachem discus buffer works well and lowers pH more predictably. However it is not cheap and ppl complan about the high phosphates it causes. If peat works well, I wont be buying another tub of the buffer.
Edited by deliriouz, 09 April 2014 - 12:10 AM.