Good news. We’ve actively used the OA system for 50 days with no major catastrophes. Celebrated by spending the day water sampling and cleaning oyster poop; here’s the summary:

• Primed the pH probe with low pH water from tank 2
• Labeled bottles
• Picked up Rick’s Sond to measure salinity
• Animals were being fed (header tank was ~3/4 full). Because I was planning on draining them in an hour or so, I turned off the flow from the header tanks to the culture tanks to let the oysters eat.
• Took water samples @ 1pm
• Measured grab samples for T, S & pH. I’ve been using both our salinity probe (even though it appeared broken, was trying to record uS/cm in case it was reading correctly), and Rick’s Sond, but today the glass bulb on our salinity probe broke off. I only recorded Salinity via the Sond. Finished measuring @ 1:45pm.
• Injected HgCl into bottle samples; finished this @ 2:05pm.
• Cleaned all tanks. Method:
  • Remove Olys and place in tray
  • Use large siphon to drain; when water level gets low I tip the tank on its edge to drain as much water as possible. Then I remove the probes if they are in there and place in a tri-pour with their respective treatment water.
  • Carry the tank to the floor, thoroughly spray gigas in tank with fresh water to remove large particles/feces. This time I counted the # of polychaets found in each tank, and collected the polychaets that I saw to give to Chelsea Wood - she is inspecting them to figure out which species it is. Most are found amongst the gigas - sitting on top of the valve that faces down, or in the cracks/crevaces. I found one in an Oly bag, and have seen a few in the past, but the majority are in gigas.
  • Dump gigas into tray.
  • Thoroughly spray each gigas and each oly back individually.
  • Sanitize the tank with Vortex cleaning solution, rinse with fresh water
  • Replace tank, replace cleaned animals.
  • I did not move the animals, tanks or probes around this time.
• Bleached the algae lines with 20mL 12percent bleach in 3 gallons. Let bleach water run through system (from algae lines through the lines that run into the tanks - but redirected bleach water to the floor). Rinsed lines with 3 gallons of fresh water.
• Replaced all filters

Notes:

• String/mucusy stuff re-appeared in tanks 1 & 2 in large amounts, and a small amount in tank 3. We need to sample this on Saturday if we see it.
• No gigas mortality. I have not counted Oly mortality (there are definitely a few), but will do so on Saturday when we sample.