Chemostat On 3/6 Pioreactors

Hi -
We are using a set of six Pioreactors via a leader. When setting up an experiment with the chemostat dosing automation, only three of our six pioreactors run the automation. It also seems like only those same three measure OD and output growth rate data. When we previously tried to use this set for an experiment, the other three randomly began dosing about 20 or 30 cycles later. Not sure if maybe somehow the time is misaligned across the set (is that a thing?)?

The pumps definitely work, but the problem seems to be specifically in running the chemostat automation. I can’t get the individual pumps to run the automation either, but there’s never an error (that I can see?)

Hi @kellye, welcome!

Hm, interesting problem. It’s hard to say what the problem might be currently. Can you send me your logs (“Export data” → select the experiment where you had the problem → select “Pioreactor Logs” → click export)? There’s often more information in the logs. My email is

If you’re not getting OD readings, this sounds strange. OD data isn’t a blocker for a chemostat, but suggests something else could be wrong.

Another thing to check is the software version across the workers. You can check the version by either looking at the System tab under “Pioreactors” page → “Manage” → “System” for each card or you can SSH into each worker and run pio version.

Just following up on this for future readers: the culprit was seconds_per_sample was very low for these Pioreactors, and any dosing-automation doesn’t start until a full cycle of od_readings has occurred.