Oxygen units

Our water supply (artesian well water) can be very low in oxygen and extremely high in nitrogen and total percent gas saturation. Oxygen levels have been as low as 4.94 ppm at the source, nitrogen saturation as high as 129 percent, and total gas saturation as high as 116 percent. We constantly had problems with exopthalmia (Popeye) and problems with oxygen fluctuations. To solve this problem, oxygen units were built and installed in each raceway, using a modification of a design patented by Barnaby Watten in 1989.

Results: using approximately 0.5 liters per minute oxygen per 30 gallons per minute water

Source	Oxygen ppm	Percent nitrogen	Percent total gas	Percent oxygen
Cold water source	6.97	116.88	108.96	79.87
Below oxygen units	10.50	101.90	105.66	120.32
Warm water source	5.73	120.12	110.06	73.32
Below oxygen units	10.50	101.92	108.33	133.51

November 1998: The oxygen units that we built are very fragile. The units are made out of PVC and it is extremely easy for the welds to crack if they happen to get bumped too hard or from the freezing and thawing process as the weather changes. With just the slightest crack in one of the welds, just about all the oxygen injected is lost. On a couple of occasions we have lost a few fish due to loss of oxygen with a crack in the welds. A major mortality could result if the oxygen leaked out during times of increased fish density. To solve this problem, Roger Mellenthin came up with the idea of using fiberglass resin and cloth on all the welds. He also reinforced the reservoir by bolting the sides together then welding the PVC. By doing this, the oxygen units are much stronger and can take lots of punishment without fear of causing hairline cracks at critical points. Roger is in the process of rebuilding all the oxygen units at FES.