Thanks to all those who responded to my using bore/rain water thread.
You were all very helpful.
I have had my water tested thoroughly by a specialized fish shop and have been told the water is excellent for the fish.
However the only problem is that the Ph is off the scale - Very high Alkalinity.
I have purchased some 'ph down' chemical that will increase the acidity.
I was wondering what was the best way to add it without disrupting the fish to much and causing them to stress.
How much should i add and at what intervals???
I have a 216 ltr tank with two Oscars.
Thanks in advance.
P.S. Those who wanted to know where the water i was using is from - I am in Western Australia.