Phytoplankton Reactors

[Aged Salt]

OK, Gary, just how time-consuming would these reactors be & would they be difficult for a novice like me to contaminate the culture? I want the long answer TIA, Bob

[mesocosm]

Greetings All !


"Contamination" issues will be the next post ... first I'd like to get into the different approaches to culturing, and some of the pros vs. cons ...

Indoor Contrasted to Outdoor
Indoor culture allows control over illumination, temperature, nutrient level, contamination with predators and competing algae, whereas outdoor algal systems make it very difficult to grow specific algal cultures for extended periods.

Indoor Advantages: A high degree of control (predictable).
Indoor Disadvantages: Expensive.

Outdoor Advantages: Cheaper.
Outdoor Disadvantages: Little control (less predictable).


Open contrasted to Closed
Open cultures such as uncovered ponds and tanks (indoors or outdoors) are more readily contaminated than closed culture vessels such as tubes, flasks, carboys, bags, etc.

Open Advantages: Cheaper.
Open Disadvantages: Contamination more likely.

Closed Advantages: Contamination less likely.
Closed Disadvantages: Expensive.


Sterile (Axenic) Cultures
Axenic cultures are free of any foreign organisms such as bacteria and require a strict sterilization of all glassware, culture media and vessels to avoid contamination. The latter makes it impractical for commercial operations.

Axenic Advantages: Predictable. Less prone to crashes.
Axenic Disadvantages: Expensive. Difficult (Relatively because of "sterile technique").

Non-axenic Advantages: Cheaper. Less difficult.
Non-axenic Disadvantages: More prone to crashes.


Batch Culturing
The batch culture consists of a single inoculation of cells into a container of fertilized seawater followed by a growing period of several days and finally harvesting when the algal population reaches its maximum or near-maximum density. In practice, algae are transferred to larger culture volumes prior to reaching the stationary phase and the larger culture volumes are then brought to a maximum density and harvested. The following consecutive stages might be utilized: test tubes, 2 l flasks, 5 and 20 l carboys, 160 l cylinders, 500 l indoor tanks, 5,000 l to 25,000 l outdoor tanks.

Batch Advantages: Easiest. Most reliable.
Batch Disadvantages: Less efficient. Quality may be inconsistent.


Continuous Culturing
The continuous culture method, (i.e. a culture in which a supply of fertilized seawater is continuously pumped into a growth chamber and the excess culture is simultaneously washed out), permits the maintenance of cultures very close to the maximum growth rate.

Continuous Advantages: Efficient, provides a consistent supply of high-quality cells, automation, highest rate of production over extended periods.
Continuous Disadvantages: Difficult, usually only possible to culture small quantities, complex, equipment expenses may be high.


Semi-Continuous Culturing
The semi-continuous technique prolongs the use of large tank cultures by partial periodic harvesting followed immediately by topping up to the original volume and supplementing with nutrients to achieve the original level of enrichment. The culture is grown up again, partially harvested, etc. Semi-continuous cultures may be indoors or outdoors, but usually their duration is unpredictable. Competitors, predators and/or contaminants and metabolites eventually build up, rendering the culture unsuitable for further use. Since the culture is not harvested completely, the semi-continuous method yields more algae than the batch method for a given tank size.

Semi-continuous Advantages: Easier, somewhat efficient.
Semi-Continuous Disadvantages: Sporadic quality, less reliable.



No ... I'm not this smart. The above information is extracted directly from:

FAO Fisheries Technical Paper 361
Anchored Link to Algal culture techniques




In reviewing the posts of folks engaged in home phytoplankton culturing during the past few years, it is apparent that someone, somewhere is applying virtually every possible combination of these factors ... pretty cool, actually. Having said that, two "main strategies" are prevalent:

(1) Indoor / Open / Non-axenic / Semi-Continuous.
(2) Indoor / Closed / Axenic / Batch.

The results that folks report breakdown pretty much along the lines suggested in the "advantages vs. disadvantages" outlined previously ... with much dependent upon husbandry skills.

What else is new? ...

The other pattern that emerges has to do with what folks are trying to do with their cultures ... not surprisingly. Folks engaged with a culturing strategy targeted on a "general ecosystem feeding" of corals and filter feeders are pursuing techniques which emphasize ease and cost effectiveness (Indoor / Open / Non-axenic / Semi-Continuous). Folks who are engaged in a culturing strategy targeted on feeding a "prey specific" species or more specialized ecosystem are pursuing more "advanced" techniques, with less emphasis on cost and ease while emphasizing "quality" and culture control (Indoor / Closed / Axenic / Batch).



FYI

[majesticangelfish]

The continuous culture method, (i.e. a culture in which a supply of fertilized seawater is continuously pumped into a growth chamber and the excess culture is simultaneously washed out), permits the maintenance of cultures very close to the maximum growth rate.

Hi Mate, How could we Build one of these "reactors" (indoor).

-Would the Zooplankton get into the growth chamber (If water is Recirc. tank>Reactor+fertilizer>tank)-and crash it? If so, how could one prevent this (UV/Ozone- before the culture reactor?)

-Is there a large risk of the "Fertilized seawater" not being utilized(via phytoplankton), and ending up in our captive ecosystem?

What type of fertilizer should be used? Should CO2 be added?

Cheers

[OUinLA]

Bob, i've recently started some greenwater cultures and some L strain rotifers. It's probably the easiest thing to do in this hobby. Check out these links
http://www.advancedaquarist.com/issu...02/breeder.htm
http://www.advancedaquarist.com/issu...02/breeder.htm

Just don't get any rotifers into the green water and remember to harvest both cultures regularly for optimum growth and nutritional value.

[Orion76]

There is tons of info on the web on the home culture of phyto plantkon, this would be my method of choice, the bottle method:

http://www.advancedaquarist.com/issu...02/breeder.htm

Of course using it to breed rotifers is a great way to create food for out corals, but too time consuming for many of us with all the aquarium chores we already have each day:

http://advancedaquarist.com/issues/sept2002/breeder.htm

Then of course there is the plankton culture manual which covers it all in detail:

http://www.amazon.com/gp/product/096...lance&n=283155

Gary, with regards to the other thread, of course there are plenty of benefits and uses for phytoplankton but when a newbie is all excited about the plankton reactor sales pitch he read on the Grotech website and thinks he needs to spend hundreds of dollars on a device that automatically doses phytoplantkon into his system "to feed SPS with it" I think the best advice is to tell him to save his money until he understands why and how he would want to breed / dose phytoplantkon, rather than justify his planned purchase. The beginning aquarist's funds and learning time are better invested elsewhere at that stage. JMO.

[Orion76]

Mad posted that while I was typing :shoot7:

[Orion76]

Another very good resource on culturing phyto plankton and rotifers is a book called "Clownfishes" by Joyce d. Wilkerson:

http://www.amazon.com/gp/product/189...Fencoding=UTF8

It covers Clowfish breeding, and of course baby clownfish require small prey like rotifers.