Above the Tavern with Parka!

[Parka]

To me the first thing to figure out is what kind of tap water you have.....

According to the Gwinnett Co. Ga. website the tap water has a 7.26 pH and a Hardness of 1.5 gpg. Grains per gallon, I never even heard of that measurement. I have never even measured for pH before, NOT EVER! In Ohio where I grew up we had good municipal water and the same thing here in Ga., I never had to deal with well water. Gwinnett gets their water from Lake Lanier.

I check nitrate levels though, ever since I started keeping Goldfish and Koi.

 

[duanes]

7.25 is pretty closs to being neutral, and 1.5 grains, is soft.
There are a number of ways hardness in water is measured, grains per gal is just one of those ways
When using Grains per gallon as a measure, 7 grains is moderately hard (medium), 10 grains is very hard water., 1 is soft
So using those measurements, your water seems reesonally good for Oscars, and other standard Amazonian species.
I wouldn't go buying wild caught oscars from the Rio Negro.....but aquarium strain LFS oscars should be fine.