There is an unwritten law that things will break during terrible weather, when you are short staffed, or on a Friday at 3:25.
Such was the case last Saturday when our weekend crew, Jeff and Nate, arrived to six inches of heavy snow. Now six inches of snow really doesn’t seem like a whole lot, but when you have 4 acres of overhead bird netting that needs to be shaken and far more snow to plow- in addition to taking care of 6 million fish- well, let’s just say the troops were called in. Good thing too. The problems didn’t end there.
Rob and Joe arrived and started on the snow while Jeff and Nate got on with their fish culture duties. While feeding the Chinook, Nate noticed the flow had almost stopped in one of the raceways. It was lucky raceway 13. Coincidence? I don’t think so….
|This is not what you want to see...|
|This IS what you want to see|
The flow had dropped from the usual 750 gpm (gallons per minute) to mere 100 gpm. Fortunately, the fish were doing okay. It was suspected that some of our water filtering media had broken up and gotten jammed in the valve. Usually you can break this media loose by opening and closing the valve. But this time that didn’t work.
The guys were able to install a backup pump to supply water from the adjacent raceway, pumping water from A14 to supplement the flow in A13. Both raceways had around 350 gpm each. Because of the low flows, both of these raceways off feed for the weekend. We would have to wait until Monday to take off the vacuum degasser and clear the blockage.
Alright, I know most of you can't sleep without knowing what happened on lucky raceway 13. The great news is that we got the valve cleared! It took some wrestling by our fantastic maintenance guys, Terry and Adam, to get the de-gasser off, but once that was removed, the plugged Koch rings were easy to pull out.
|The culprits, plastic filter media, called Koch rings.|
Surprisingly, there were only parts and pieces from about 3 Koch rings, which goes to show that it doesn't take much of a blockage to significantly restrict flows. Of course, a fair amount of moss also came out, which was likely packing the remaining space.
Great Work Team Dworshak!
Text by Angela Feldmann and Nate WiesePhotos by Nate Wiese