Well my test is complete. I removed my packed column to remove built up iron on the plastic media and reinstalled it. (I use muriatic acid and water). Anyway, with the water just dumping into the pit below from the well through some plastic cage material (to keep out debris and animals) -- without the packed column -- D.O. is 5.5 mg/l or about 50 percent saturation. Of course after it flows downhill underground through a 4 inch PVC pipe and it goes up the upturned elbow and dumps into the trout pond it is probably a little bit higher.
Photo showing pit (disregard packed column)
After reinstalling the packed column in the photo below, D.O. jumps to 9 mg/l and just over 80 percent saturation. The tests were done with a LaMotte manual test vs. my D.O. meter. D.O. meter apparently does need some work as not only did it have problems calibrating with know mg/l, it is off in % saturation. I used "Rawson's nomagram of oxygen saturation" to calculate % saturation.
Here's a look at the top of the packed column where the well flow drops into. The top bucket is only half full of plastic media and has a homemade distribution plate to evenly distribute the flow through the holes through the packed media.
View of distribution plate installed:
Water dropping through distribution plate in half media filled top bucket.
Side view of the same thing:
Note the plastic coated wire cable used to reinforce the handle connection on the top bucket. This is important, as although initially the packed column is quite light, eventually as iron builds up on the media and buckets, the entire apparatus becomes quite heavy.
