Rotifer Culturing at Home: Continous Cultures

Rotifer Culturing at Home: Continuous Culture Set-Up and Protocol

Growing rotifers as a continuous culture is easy to do, but requires a small amount of work, almost every day. Unlike batch culturing, where the goal is to culture the most rotifers possible in sequential batches, the goal of continuous rotifer culturing is to create a long-lasting, stable, low-density culture.  To create a continuous culture at home, follow the protocol below:

rotifer culture

Materials:

  • Several feet of flexible airline tubing
  • 2 twelve inch lengths of rigid airline tubing
  • 2 buckets (old salt buckets—or other, as long as they are clean and chemical free)
  • Saltwater~1.014 specific gravity
  • Live phytoplankton culture (for use as rotifer food)
  • Rotifer starter culture harvested from your batch culture

Protocol:

  • Take approximately 1.5 liters from your ready-to-harvest rotifer batch culture, as listed in the previous protocol.  Add the volume to your first culture bucket.
  • Add two liters of salt water to increase the culture volume
  • Add enough phytoplankton to the culture to turn the culture to a light green color
  • Attach the flexible airline tubing to the rigid airline tubing at one end and to the air pump on the other end and insert the tubing into the bucket to, create a moderate flow of bubbles.
  • For each day over the next week, add approximately 2 more liters of saltwater and enough phytoplankton to  tint the water a light green
  • When you have about four gallons of culture, pour half of the volume into the second culture bucket, add about 2 gallons of saltwater to each of the two buckets and insert the airline tubing to create a moderate flow of bubbles
  • Add enough phytoplankton to tint the cultures each light green
  • Final step: Every day, harvest about 2L to 1 Gallon of culture, replace the volume with new saltwater and tint the water light green with fresh phytoplankton

Saltwater Aquarium Blog Tip:
The key is to add just enough phytoplankton so that the culture turns a light green color—and that the rotifers are able to clear the phytoplankton every day.  If you add too much, there is a risk that the density gets so high that the culture will crash.  So add modestly and consistently

Advanced Aquarists Tip:
As you get more confidence with your culturing technique, you can control the density by varying the amount of phytoplankton that you feed them.  If your fish have just spawned or you need more rotifers for whatever reason, you can get a ‘burst’ of rotifers by spiking the culture with more phytoplankton.  Be warned however that the higher density the greater the risk of the culture crashing—so if you spike, make sure you harvest aggressively and keep replacing the water volume
This post was the fourth entry in a series about culturing saltwater rotifers.

Return to the previous post  about batch culturing rotifers

Go back to the first post in this series by clicking here

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