Nannochloropsis settling on bottom?

[plankton]

I’ve started tetra and Nanno batches three days ago and noticed that both tend to settle on bottom. Is this because they are going dorment or not enough flow? I smelled all four bottles and there isn’t rotten smell.

I started with 20ml of stock solutions to 1L of 1.019 freshly made salt water that I aged for 24 hours plus 1ml F2.

 

[ichthyogeek]

What containers are you using to culture the microalgaes in? Typically, round containers that taper towards the bottom (like inverted soda bottles) are good for this type of culture. It's looking like you're using a square container, which isn't the worst, but it does weird things to flow.

And where are you putting the airline? In the center of the bottom of the container? Towards the side of the bottom? I'd recommend putting the airline smack dab in the middle unless you have multiple airlines going at once.

 

[ichthyogeek]

I had similar issues with culturing Rhodomonas in large (20L) carboys. They were round, and big, and a single airline didn't cut it. What did end up working, was using multiple airlines situated equidistant from each other. In your case, what might work, would be putting four airlines in the corners of the container, which would help with flow patterns and prevent any dead spots from forming within the container.

If the container is tapered, then I would recommend first getting rid of the settled microalgae, and then putting more air into the culture to increase flow.

 

[plankton]

Thanks for your prompt replies!

I fed the algae that collectors in dead spots to theTigriopus and added additional flex air house until my shipment of hard comes in. I also increased airflow because these water bottles are basically flat bottomed. Lesson learned and be in on the lookout for round bottom or inverted cone shaped.