For optimum dosage of CO
Therefore, a solenoid valve is switched between the pressure regulator and the bubble counter. The best
solution - in any case - is to use an automatic CO
that much CO
is added to the culture that is used by the algae. In addition, the pH is always kept in the
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right range. The pH probe can be placed in the top of the plankton light reactor. For marine microalgae,
the pH should be set to pH 7,5.
3.2. Zooplankton production in the plankton reactor:
For the plankton reactor, the same conditions can be applied as for the plankton light reactor. Cleanness
is the most important condition also for the production of zooplankton. However, it is not necessary to
cook the media before use. For starting, the plankton reactor is filled with clean fresh prepared sea water.
As food microalgae from the plankton light reactor are added, the colour is slightly green.
If the plankton reactor is run with rotifers, the inoculating culture can now be. If Artemia shall be raised,
the reactor can be inoculated with Artemia eggs. We recommend to use decapsulated eggs. This avoids
trouble with the hard residues of the shells. Decapsulated Artemia eggs are available at your local dealer
- life A from Aqua Medic.
Cultivation of Zooplankton – rotifers (Brachionus):
For producing rotifers, we strongly recommend to use the complete 2 stage food chain. Brachionus cultures
that are fed with living microalgae are much more healthy and viable than cultures fed with yeast of liquid
foods. As it is not good for a rotifer culture to stay without food for some days, the microalgal culture in
the plankton light reactor should be set up first before the zooplankton culture is started. To check the
Brachionus culture, we recommend to use a magnifiing glass (best is a stereo microscope) with a
magnification of approx. 20 fold and some petri dishes for observation.
In a healthy Brachionus culture that doubles every 4 days always minimum 25% of the animals should
carry eggs. The stomach of the animals should be filled with algae (green) and move around quickly. If no
egg carrying animals are there and the body is transparent and the animals swim only slowly, this is a
clear indication for food shortage.
3.3. Set up of the food chain:
If the complete food chain is set up, healthy cultures can be maintained for long term, if the cleanness is
always guaranteed.
It is recommended to keep a strict rhythm of feeding and harvesting the cultures. The following pattern
has proven to be succcessful:
Daily 0.8 - 1 l are harvested from the algal culture. The reactor is then filled up with the same amount of
fresh seawater and each 1 ml ferreal + spureal and floreal + iodare added. The sea water you may take
water from a reef aquarium, has to be filtered through a filter with small pore size (e. g. a 5 µm filter from
the reverse osmosis unit) so that no zooplankton can enter the culture.
From the rotifer culture, also 0.8 - 1 l are harvested for feeding. The rotifer culture is then filled up with
the harvest of the algal culture. If you need more algal culture for direct feeding to invertebrates or as
reserve, you can increase the daily harvest of the microalgal culture up to 1.5 l.
For a short period of higher demand, you can also increase the harvest of the rotifer culture to a maximum
of 2 l/day. However, in this case the algal culture has to be in a top condition - for a longer period, this is
not recommended, as the culture may break down suddenly.
3.4. Automation of the system with dosing pumps:
The plankton cultures need daily maintenance. Both, the algal and the rotifer culture have to be harvested,
diluted and fed daily to keep the high growth rate. This effort can be minimized by using dosing pumps.
We recommend the peristaltic pump SP 3000 from Aqua Medic.
Following, a system is described where an aquarium with invertebrates is supplied with live plankton every
day:
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, we recommend to use a night shut off - to avoid a pH drop during the night.
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control unit with a pH controller. This ensures that only
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