O2 experiment failure

The O2 experiment was a failure. Why? Because both beers turned out great. The non O2 beer finished at 1.008 and the O2 beer finished at 1.006. The O2 beer tasted better. It was smoother. But the non O2 beer was very good as well.

Ok. So I didn't nail down my culprit of yucky taste. Below is a list of differences from the offending brews that I can think of.

1. The current brew was aged in the bath tube. The others in the chest freezer.
2. The current brew used a silicon air lock. The others used a water air lock.
3. The current brew used a glass thermometer. The other used an uncalibrated steel thermometer.
4. The current brew was brewed with Albertson's spring water. At least one of the other was Arrowhead. Although now that I think about it one of these Kevin's water. So this seems unlikely.
5. The previous brews were sampled at 1 week. The current brew was left alone for 3 weeks and then sampled.
6. Also fly sparged instead of batch sparged.

I think I'm going to mix them both in the keg and pour out what horrid abomination is in there now.