Which Culture Should I Grow?



Which strains are good for the classroom?    


We like reliable, fast-growing strains that are not fickle or invasive (none of our strains are invasive). A few of our favorites are listed below. Note that our Algae Beads kit is a good alternative to growing free-living cultures, and that our Brainy Brinys kit is an excellent model predator-prey system. 


One of our favorite freshwater strains is Spirulina, a blue green extremophilic algae that prefers high pH (around pH 10). This pH is advantageous as it limits competition from other algae, freeing you from worrying about contamination. They are giants in the microbe world, allowing you to harvest them with a simple mesh screen. They are non-toxic and consumed around the world for their protein and antioxidant properties. Our Spirulina Culture Kit is linked hereChlorella is also a hardy freshwater species, one which we use to make our Algae Beads. Our Chlorella Culture Kit is linked here


For seawater-based projects, we recommend Nannochloropsis. It is a small and hardy plankter (2 um) that grows very quickly and responds to changes in salinity, nutrients, and toxins with corresponding changes in biomass. Our Nannochloropsis Culture Kit is linked here.


As mentioned above, our Brainy Briny kit is an excellent alternative to algae-only culturing and adds an additional layer of excitement to scientific discovery! It contains feedstock algal cultures as well as brine shrimp predators, which when combined make for a simple and easy predator-prey model system. 


Which strains are best for research projects?


Favorites:  Spirulina, Nannochloropsis, and Chlorella vulgaris.


You should consider your research goal. Choose a strain that best emulates your system (freshwater or seawater,  diatom or dinoflagellate, green or blue-green). The most important thing is that you want to test your hypothesis, not test if you CAN grow algae. So choose a strain that is not going to be troublesome to grow, and that allows you to draw conclusions applicable to your hypothesis. Browse our Organisms page to identify the strain that works best for you! 


Which strains of algae do people eat?

People eat Spirulina, Chlorella vulgaris, and Chlorella pyrenoidosa.  However, we recommend buying algae to eat that is packaged for that purpose.  We at ARS offer no guarantee, warranty, or prediction of safety if algae we sell is consumed by humans or animals.  While these strains are routinely eaten, quality control systems are in place to make sure that they are safe. Our strains are clean and reliable, but once it leaves our doors, all bets are off. Oh, and please don’t call us and ask how much urine you should use to culture spirulina, because we've been asked before and the answer is none.  


Which strains are best for feeding to aquariums?

  • Seawater Favorites:  Isochrysis, Nannochloropsis, Tetracelmis, Porphyridium, and Thalassiosira.  And of course Brine shrimp.  
  • Freshwater Favorites:  Chlorella vulgaris, Chlorella pyrenoidosa, Navicula, and spirulina (but you will need to wash the spirulina to remove its extremophile media)
  • Feeding filter feeders? Find the size class that your filter feeder can strain organisms from the water, and get a feed that it can capture.  
  • Improving water quality?  You want a fast grower, with a high capacity for “Luxury Uptake”.  Nannochloropsis is your algae It will grow fast, gobble up all the excess nitrogen and phosphorus. Then be eaten or grabbed by your filter.  


Which strains represent algae blooms?

Favorites:  Anabaena, Nannochloropsis, spirulina, dinoflagellates, Chlorella


To study algae blooms, you need an algae that will reliably grow.  All the strains above will do that well.  Anabaena, is a blue-green algae and  is commonly found in algae blooms in lakes.  Chlorella is another freshwater strain, but it is less commonly found as a problem, but it grows very well.  Dinoflagellates, Prorocentrum for instance are marine strains, and dinos are commonly part of nearshore blooms.  Most strains can be used to model a bloom, pick it and justify using it in your paper by saying that it is easy to grow and from an appropriate group of algae.  



What Kind of Container Should I Use?


Containers for Experiments

Favorites:   Centrifuge tubes (50mL), Beaker Bags (500mL),  Empty water bottles, Tissue Culture Flasks (50, 250, 600mL)


For experiments we have four recommendations, largely based off of culture volume

  • Centrifuge Tubes, 50mL: For small cultures, we recommend self standing centrifuge tubes.  They are relatively inexpensive, easily moved, and completely reusable.
  • Beaker Bags, 500mL,  Larger culture volumes, we recommend using our Beaker Bags (500mL).  They stand up on their own, easily moved, and are completely reusable.  A good volume to grow brine shrimp is 500mL.
  • Empty water bottles are great!  It feels good to recycle, doesn’t it? .  Be sure to keep the lids open to allow for gas exchange.
  • Tissue culture flasks are some of our favorites,  Useful for getting cultures close together to be exposed to a single light source.  We suggest using our vented cap products.


Containers for Large Cultures

  • Aquarium 10-gallon, glass.  We recommend 10-gallon glass aquariums. Easy to buy locally from your pet shop (shipping is not recommended).  We manufacture lids and LED lights (should be released soon).  This is a work horse of many a lab and classroom.  After your algae project is over, we recommend goldfish.
  • Aquariums, larger than 10-gallons.  Growing to 10-100 gallons.  Aquariums can be useful, but can be limited by the amount of light that can pass through the culture. For larger cultures make sure you are mixing well to move the culture around to give each cell an exposure to the light.  We love solar tubes (link, can we get a contract to resell, or 5% to recommend).  
  • Ponds,100-gallons and larger.  Covered or open-ponds.  They are where most of the world's algae is grown. Any ideas on how to cultivate at sea? It is our goal to reduce CO2 in the atmosphere.  Call us if you have a good idea!  We want to believe!!!



Do I Need a Heater?



  • Probably yes, maybe no.  Most strains will do well at temperatures that humans find favorable.  In the 21-32C (71-90F) you get the best response for most of our strains.  Each strain is a bit different (read great research project!)  The higher temperature will result in faster growing algae.  So, if you are in a rush- warm it up (you know who I’m talking about as a high school science project student).
  • Here are some that we have data on:
  • Spirulina vs temperature
  • Too hot is over 100F, most algae will die promptly at 104F.  It is best not to tempt fate.



Do I Need a Light?

  • You will need light of some kind.  We recommend LEDs or CFLs.  We wrote a great article about it here(LINK).
  • Sunlight can be OK, but it is often too much light.  For reference, sunlight is ~2500uE/m2s and the saturation of most phytoplankton is 120uE/m2s.  That means that the extra light will need to be discarded by the algae, so it does not die.  It costs the algae energy to dispose of the light.  We never recommend a culture under 20L get direct sunlight.  
  • More on light- see this link.



Do I Need Salts and Nutrients?


Yes!!!   You will need BOTH salts and nutrients to grow the algae!!!



Consider the salts as the physical environment for the cultures.  Even freshwater cultures need some salts.  Salts generally include the ions: Chloride, Sodium, Magnesium, Sulphate, Calcium and Potassium.  We make our culture salts with pH buffers to make the culture more resistant to swings in pH (photosynthesis pulls CO2 out of the water and drives the pH up- story).



Most folks are familiar with fertilizer for their gardens, this is very similar, but formulated for algae, not terrestrial plants.  Our nutrients are custom blended and usable in freshwater and seawater cultures.  


‘Media’ is what we call the mixture of salts and nutrients.




Examples of a setup?


  • You will need the following to get the cultures going.
  • Culture
  • Container
  • Salts
  • Nutrients
  • Lights
  • Heaters



I'm ready to start culturing! What do I do next? 
Visit our Starting a Project page to discover your next steps!