The first thing you have to do:

When you receive your your culture, please immediately follow the instructions described in the “Immediate Culture Care” section (following this section). You will also have received a hard-copy of the Immediate Culture Care instructions with your culture.

After receiving your culture immediately take the following steps

Step 1

Give it a gentle shake and open the top of the culture bottle to allow it to breathe.   

If you are not immediately ready for Step 2 then then place it in shaded sunlight.  Be sure to agitate your culture a few times a day by gently shaking the bottle.

Step 2

Transfer the culture to a transparent container.

Any clean, non-reactive, transparent container will do.  Glass is always better though.  The container used should be larger than the volume of the culture you received, but not too big.  It is best to use a container that is taller than it is broad.  Glass jars or dink bottles are perfect.  

As a guide

• For 50mls of culture, transfer to a container that’s around 100 - 250mls
• For 500mls or 1000mls of culture, transfer to a 2L – 4L container

Step 3

Bubble air through the culture.

The purpose of bubbling air through the culture is to facilitate gas exchange and, more importantly, to mix the culture so that each strand of spirulina (the trichomes) get to spend some time in the light, but not too much time. 

You will need:

1. An aquarium air pump
2. Silicone tubing
3. An in-line air valve

1. Select and appropriate length of tube and cut it about 1/3 of the length.  Join the two pieces with the in-line valve.  
2. Fix the short end of the tube to the pump outlet and open the valve.
3. place the tube into the culture vessel and turn on the pump.
4. Adjust the pump so the bubbles are vigorous enough to mix the culture but not too aggressive.

Step 4

Place the culture in gentle indirect sunlight.

Do not, at this stage, place your culture in direct sunlight. This is important because the organism cannot handle an intense light load when it is at a small volume and is unable to self-shade. You run the risk of overloading its photosynthetic apparatus and also overheating the culture. 

You could place the culture in a sunny location but cover it with a cloth that does not let all the light through. 

As the culture becomes larger and denser, it can self-shade and will do better in direct sunlight.

Step 5

Monitor temperature

Spirulina can live at temperatures between 2 – 40^oC. However, it will thrive and vigorously multiply between 27 – 37^oC. So, if you live in a cold place, take steps to maintain the temperature of your culture to at least above 15^oC and ideally between 27 and 37^oC.

It is important to monitor the temperature of small volumes because when they are in the sun they can rapidly heat up. If you are not vigilant you can lose a culture at this stage through over heating.
You might like to buy a digital thermometer with a probe to monitor the culture’s temperature. You may also consider purchasing a USB heat matt to keep the young culture warm. Both of these items are cheap on eBay.

Step 6

Prepare for the next stage

Your culture can survive comfortably under the conditions described above for a long time. However, to  gain the benefits of Spirulina, you will need to increase the volume. Therefore, the next step will be to increase the volume of your culture.

The quick guide section below details how you build up to 10L – 15L. Please follow these instructions carefully to ensure you end up with a healthy, thriving culture.  While 10 – 15L represents a solid volume to work with and build on, you will need at least 80 – 100L to harvest meaningful amounts of spirulina

Before working with your culture a few notes on hygiene and safety:

hygiene

• Before transferring your culture to a new container always give the container a good wash with hot soapy water followed by a thorough rinse with clean water.  Some people also take the extra precaution of spraying their equipment and containers with a surface disinfectant before cleaning.
• Wash your hands before handling Spirulina equipment and or putting your hands in the culture.  Remember, there are literally 1000s of microorganisms on your skin.  You could also use disposable latex gloves to be extra sure. 
• Keep your equipment clean. Wash whatever you put in contact with the culture.  Warm soapy water works best with a final fresh water rinse.  The cleaner the better.
• Remember you are aiming to keep your culture pure and clean because you will end up eating it.  Having said this, the pH of your culture does a lot of work. Once the pH gets up to 10 and over - not many potentially troublesome organisms can survive

Saftey

Notes about this guide 

The purpose of this quick guide is to get you expanding the culture in an easy to follow step by step way so you end up with at least 10L of healthy culture.  You will need a lot more, at least 80 - 100L, to have a good working volume.  However 10L is a good start and is a stable amount.  How to set up your final working Spirulina tank (bioreactor) and build up to the final culture volume is described in detail in the rest of the manual.

This Quick Guide assumes you have taken the steps described in the immediate culture care section above. By now you should:

• Have transferred the culture to a larger transparent container
• Be bubbling air through the culture so that it is in constant motion
• Have placed your culture in the sunlight
• Be monitoring the temperature

Step 1

Make up the nutrient solution

To begin expanding the culture you will need to make up an appropriate amount of nutrient solution.  An appropriate amount means making enough to undertake a few cycles of expansion.  You don't want to have large amounts of culture media sitting around running the risk of being contaminated.

If you are starting off with 500 ml and you are adding roughly 1/3 of the volume you will need 160 ml of nutrient media.  For the next expansion you will need (500+160)/3 = 220ml.  Thus for 2 rounds ofculture increase you will need to have made up a about 400ml of nutrient media.

To make up the media follow the instructions in the  “Making up the Nutrient Solution” section below.  Remember to use dechlorinated water.  There is more about water in the basic elements section of this manual.

Step 2

Add nutrient solution

• Before adding nutrient solution to the culture, note its shade of green.  This is a good reference point to indicate when you will next need to expand your culture.
• Add nutrient solution at a rate of roughly 1/3 of the current volume of the culture. This is important because you don’t want to dilute it too much and make it weak and vulnerable to sun damage.  The table below give you an indication of how much nutrient media to add to a given volume of culture. 

• Make sure the culture and nutrient solution are at about the same temperature. Spirulina doesn’t like sudden temperature fluctuations.
• The Spirulina will multiply and grow into this new volume in 2 – 3 days if you are maintaining optimal temperature and it has at least 12 hours of light per day (more is better).
• Note the shade of green in this more dilute  culture.   Before you increase again you want youe culture to return to the same shade of green your culture was before adding the nutrient media.

Step 3

Monitor temperature

Step 4

Monitor Culture Colour

Keep an eye on the colour of the culture. As it grows into the new volume it will become denser and thus darker green.

When the colour returns to the original shade of green that you would have noted at the beginning of step 2 then go to step 5.

It should take 2 – 3 days under warm sunny conditions for the culture to grow into the new volume and turn dark green.

If the culture colour is not turning darker green and is yellowing this signifies there is a problem.  Go to the troubleshooting section.

Step 5

Add more nutrient solution

• Remember, you add roughly 1/3 of the current volume.
• If you started off with 50ml you now have about 65ml from the last time you added the nutrient solution. So this time you would add roughly a 1/3 of 65ml which is about 20ml (you don’t need to be super exact).
• If you started with 500ml you would now have about 650 ml so you would add about 220ml.
• If you started with 1000ml you should now have about 1330ml so you would add about 450ml

Repeat Steps 3 to 5

• Continue to monitor the temperature. Remember the sweet spot is between 27 – 37^oC. Make sure that the young culture is not in the full sunlight all day or it may overheat and or get sunburned. 
• Each time you add more nutrient media remember you add 1/3 of the present volume. The amount you add each cycle will increase each  to account for what you added in the last cycle.
• Repeat steps 2 - 5 until the current culture vessel is full.

Step 6

transfer culture to a larger container

Step 7

Make a secchi disk.

To more accurately estimate the density of your culture, and thus when to increase the volume or harvest, make up a secchi disk.  

Instructions to do this are detailed in the equipment section below.

Repeat Steps 3 to 6

Step 8

Establish a backup culture.

Step 9

Read the rest of this guide and plan your next action.

You are strongly encouraged at this point to read the rest of this guide. If you are unsure about anything, then seek clarification from us. Once you read the following sections, you will know how to set up your Spirulina bioreactor, care for it and harvest the Spirulina.

Step 1

Decide how much Nutrient solution to make up

Decide on the amount of nutrient solution you want to make up. We advise you to only make enough for 2 -3 volume increases.  Remember the nutrient solution is a perfect media for other algae.  So to reduce the chances of your nutrient solution being overrun with an unwanted organism keep stored volumes to a minimum.

Store the unused nutrient solution in a clean sealed vessel.  Place in a dark place if you are using a transparent container.

Step 2

Weigh out the nutrient salts 

Using an appropriately sized container add the desired weight of part A salts for the volume you intend to make up.  See the weights and volumes in the table below .  For example, if you wanted to make up 500ml of solution, find 500 on the top row of the table below.  Directly under the "500" in the second row you will find the weight of Part A to add, in this case 10g.  The row below that shows how much Part B to add.  In this case 0.5 ml.  You add this after you dissolve the salts in the appropriate amount of water.

Step 3

Add water 

Step 4

Give the Nutrient solution a good mix

Mix until the solid Fast Grow Starter Nutrient Mix Part A is completely dissolved in the water.

Step 5

Add part b

Step 6

Store left over Nutrient Mix in a cool, dark place.

Purpose of this section

You could follow the steps in the The Quick Guide section and end up with 100s of liters of healthy spirulina.  As you may have gathered, growing spirulina is not rocket science.  However, as with getting proficient at anything,  it pays to have a deeper understanding of the key elements involved so you can more easily trouble shoot, make adjustments or innovate. This section  provides more information on the important elements that will influence the health and productivity of your spirulina culture.

Light

Sunlight is best

Spirulina is a highly efficient photosynthetic organism that uses a broad range of light, with a special reliance on orange and red light captured by its unique phycocyanin pigment, complemented by the standard blue and red absorption of chlorophyll-a.
A typical light abosorption spectrum for spirulina looks like this:

• ~430 nm (Blue): Absorbed by Chlorophyll-a and Carotenoids.
• ~620 nm (Orange): Absorbed strongly by Phycocyanin.
• ~680 nm (Red): Absorbed by Chlorophyll-a and Allophycocyanin.

However, with sunlight, there are two caveats to the more-light-the-better rule:

1. Sunlight carries a lot of energy and will heat your culture tank (bioreactor) up very quickly, particularly if the ambient temperature is hot. That is why it is important to monitor the temperature of your culture. You may need to shade the bioreactor to reduce the heat load during the hottest times of the day. Remember, you don't want your culture getting hotter than 42^oC.
2. When the culture is young and not very dense, too much sunshine can hurt them. They get sunburnt. Therefore, when you are growing your culture up after first receiving it you will need to shade it. You can do this by placing some see through fabric over the culture vessel.

As your culture grows and becomes denser it will shade itself. When assessing if you should shade your culture the general rule is: if you can see all the way through the culture, or most of the way in, then you should shade it.

Artificial light

While spirulina thrives in bright, natural sunlight, achieving consistent, year-round growth often requires supplemental or fully artificial lighting. This is especially true if you are growing indoors, in a garage, or in a location with limited winter sun. The good news is that spirulina does not require overly complex or expensive lighting setups. The key is to provide the right type and amount of light for your culture to photosynthesize efficiently.

The intensity and duration of light are also important. Your spirulina culture thrives if it can receive 10 to 18 hours of light per day, which can be easily managed with a simple plug-in timer. The light should be suspended close to the surface of the culture—typically 15 to 30 centimeters (6 to 12 inches) above the tank—to ensure the light penetrates effectively. A useful sign that your lighting is sufficient is a rich, dark blue-green colour; if the culture appears pale or yellowish, it is likely light-starved. Remember, spirulina does require a dark period to respire, so a consistent daily cycle of light and darkness is essential for healthy, sustained growth.

Temperature

Every organism has temperature maxima and minima, beyond which, they will not survive. They will also have an optimal temperature range, within which, they will thrive. For Spirulina, the maxima and minima are from 2^oC to 45^oC. Thus, if you let the temperature of your culture go beyond these limits it may die. This is the most common cause of culture death, particularly in warm sunny climates, when the culture volume is small.
The culture will start to grow at temperatures over 15^oC.  However, you will get optimal growth at temperatures between 27 – 37ºC. 

Outdoor temperatures fluctuate on a day-night cycle as the sun comes and goes. Many organisms, like Spirulina, are adapted to this and prefer a smooth diurnal temperature fluctuation rather than a constant temperature. Remember, Spirulina is an ancient organism and is kind of set in its ways.
The bottom line is that it is good for the culture to get a bit cooler during the night and warmer during the day. What Spirulina does not like, is sudden temperature fluctuations.  This can occur when adding growth media, which has a large difference in temperature, to the culture; beware of doing this.
TAKE HOME MESSAGE – the temperature is important to monitor and control.  If the temperature is too cold use an aquarium heater and if it gets too warm then shade it.

Important equipment to have.

Water

Most of the growth medium is composed of water.  Water with some dissolved nutrients. As such the quality of the water is important because Spirulina will absorb whatever is in its environment. This means that it will accumulate heavy metals and other toxins if they are present in the water, which is not good because the whole point of growing Spirulina is to eat it and be healthy.

•  Bottled water: This is good at the start but can get a bit expensive if you have a large bioreactor.
• Fresh, river or spring water can also be used as long as it has been sanitized using either UV light or a carbon filter (the Brita type). This is necessary to remove other micro-organisms such as algae or protozoa which can compete with or eat the spirulina. This is more of a risk at the start of the culture when the culture is still weak and the pH is still relatively low.

pH

The pH is a measure of the number of hydrogen ions in a solution. Another way of saying this is, pH indicates the acidity or alkalinity of a solution.

The pH scale goes from 0 to 14 and is measured on a base 10 logarithmic scale which means that when the pH increases by 1, the actual alkalizing activity increases by an order of magnitude. For example, a pH of 2 represents a 100-fold increase from pH of 1. A pH of 3 represents a 1000-fold increase. 

Maintaining the correct pH level is  important for successfully growing healthy spirulina.

Spirulina thrives in a distinctly alkaline environment, typically between pH 8.3 and 10.5. This specific range is essential because it directly controls the availability of nutrients in the medium.  When the pH is correct, spirulina can efficiently absorb the carbon dioxide and minerals it needs for photosynthesis and growth. If the pH drifts outside this optimal window, key nutrients like iron can become "locked up" and unavailable, leading to slowed growth, pale color, and poor health in your culture. Think of pH as the key that unlocks the nutritional value of your growing solution for your spirulina.

Furthermore, the alkalinity of the water serves as a powerful natural defense system. Most common contaminants, such as green algae and predatory zooplankton, cannot survive in the harsh, high-pH conditions that spirulina loves. By diligently keeping your culture within the target alkaline range, you are not only feeding your spirulina but also creating an environment that is naturally resistant to invasion. 

Generally if you have the well formulated stating nutrient mix, such as our Fast Grow pack, the starting pH will be around 8.5.  As the culture grows and metabolizes it slowly increases the pH.  We recommend only harvesting spirulina once the pH reaches 10.  This greatly reduces the risk of ingesting potentially harmful organisms.

Once the pH goes past 11 the growth rate will slow down.  You can reduce the pH by pumping CO2 through the culture or adding diluted vinegar.  However, we would recommend renewing all or part of the medium by starting fresh.  You can do this by harvesting out the spirulina and discarding all or part of the filtrate and replacing it with fresh medium.

nutrients

Spirulina needs nutrients grow and thrive.  You have to feed it,

The Macro Nutrient Requirements:

Providing a balanced and readily available supply of the four main macronutrients in the culture medium is non-negotiable for achieving rapid, healthy, and high-yield spirulina production. These macro nutrients are as follows

Carbon (C).  As with all life on earth carbo  forms the backbone of most organic molecules that make up the body of living creatures.  Spirulina is no exception to this and thus requires a source of carbon to multiply.  Like other photosynthetic organisms it manufactures the organic molecules it requires by using light energy to metabolize carbon dioxide. 

When you grow spirulina it uses the small amount of CO2 that is able to dissolve in the water that it is cultured in. However, to increase the growth rate of the culture we need to significantly the boost the available CO2 by adding sodium bicarbonate or baking soda (NaCO3).

Nitrogen (N). Nitrogen is the most crucial of the macro nutrients, as it is the central component of proteins, which constitute up to 60-70% of spirulina's dry weight, and of chlorophyll, which is essential for photosynthesis  Spirulina, and plants in general, use nitrogen in the "fixed" format. That is, elemental nitrogen (N) bonded with other elements, such as oxygen to make nitrate (NO3-1) or urea, which is nitrogen bonded with oxygen, carbon, and hydrogen (NH2CONH2). In these formats, the nitrogen is soluble in water and thus available for uptake by the reproducing Spirulina.  

Potassium Nitrate is a common source of nitrogen salt used for fertilizing crops and, in this case, Spirulina.  This compound has the added advantage of also supplying potassium, which is another vital macro nutrient.

Potassium (K) and phosphorus (P). Potassium is vital for enzyme activation and maintaining the internal electrical balance of the cells, while Phosphorus is a key component of ATP (the energy currency of the cell) and nucleic acids (DNA/RNA). 

secondary nutrients and micronutrients :

While macronutrients form the foundation of spirulina's growth, a healthy culture also depends on a suite of secondary nutrients and micronutrients. Secondary nutrients, including Magnesium (Mg) and Sulfur (S), are required in smaller but still significant amounts; magnesium is the central atom in the chlorophyll molecule, making it essential for photosynthesis, while sulfur is a key component of certain amino acids and vitamins.

The micronutrients, or trace elements, are needed only in minute quantities but are just as critical. Chief among these is Iron (Fe), which is a vital part of the electron transport chain during photosynthesis and is often the first deficiency to appear, signaled by a paling of the culture's blue-green color.

Other essential trace elements include Zinc (Zn), Copper (Cu), Calcium(Ca), and Molybdenum (Mo), which act as co-factors for a wide range of enzymes driving cellular processes.

For the hobby grower, these nutrients are typically supplied through a pre-mixed mineral solution or a carefully balanced blend of individual food-grade salts to ensure the spirulina has access to the complete nutritional palette it needs to thrive.

Our Nutrient Blends :

We supply 2 nutrient blends.  Fast Grow and Postharvest Nutrients.

Agitation

It is essential to keep the culture moving in sunlight hours

Note: inadequate or ineffective mixing is a very common beginners mistake.  

The easiest way to keep the culture moving is to bubble air through the bioreactor. The bubbles also facilitated gas exchange with the air. To do this all you need is an aquarium air pump, some tubing, an inline value to regulate air flow, and a suction cup to stick the tube to the bottom of the bioreactor.

One note of caution here: Make sure that the bubbles are not too aggressive otherwise they can break up the Spirulina trichomes causing losses as cells are ruptured. If this is the case, you will find the surface of the bioreactor covered in foam caused by the contents of the ruptured cells.
You can regulate the intensity of the bubbles by installing a screw value in the airline.

• You should only harvest Spirulina which is dark green. If you see brown, white, or yellow bits floating around, scoop them out of your tank and do not eat them.
• Remember to immediately wash your mesh screen after use. If you allow the Spirulina paste to dry it will be difficult to remove from the mesh pores later.
• Store harvested Spirulina paste in a clean glass container in the fridge. It will last up to 5 days. Remember, the nose knows. If it smells off then don’t eat it.
• You can also freeze excess material. Ice cube makers are perfect. Spirulina soaks up smells very rapidly so wrap your ice-cube trays with cling wrap

The best way to store your fresh spirulina is to freeze and vacuum pack it.