My oscars were pretty shy the first couple of weeks too, but then when i introduced a pair of giant gouramis to the tank they started swimming around more
Well, as said earlier I am not adding any new fish and the Oscars are just light sensitive. They still hide occasionally but at night they become pretty active and if I don't pay attention to them they swim around a lot.
That's convinient. But you still should test your water. You said they'd been acting 'shy' for 6 wks. The light hasn't been on for 6 wks. I suspect you've still got a water problem. Water is always guilty until proven innocent :-|
What about your nitrates?
How much below 80? My Oscars tank has always been at 76F and they have never been shy always active and always greet me or my girlfriend and the kids when we come into the room. If we get close to the tank they are both at the top expecting some food.
No test kit I know of tests "0.3" for nitrites. In any case they should be zero always. And you didn't test for nitrates. Super high nitrates were my guess as to what was wrong with the fish in the 1st place. By the way-test strips are not very accurate in the least, liquid kits are much better.