Picture of Simple Algae Home CO2 Scrubber - Part II Algae Cultures and Breeding
In Part I we built a simple home CO2 scrubber using algae. I'm writing this instructable to demonstrate how to culture and cultivate algae using more or less laboratory style procedures but substituting some readily available items for more traditional laboratory glassware.

I encourage you to experiment and understand how to successfully cultivate algae. The techniques and process outlined here will work for most algae strains.

Please bear with me, this is a work in progress. I normally publish open source software where the policy is "Publish early and often". The content is constantly being revised and I'm open to collaboration on many elements.

For instance the crude incubator could easily be supplemented with a sound design using plastic sheets with hinged access panels and portholes with oversized rubber gloves mounted in them. And so on.

In Part I we used a readily available algae source to create a healthy algae culture which gets fed with air, sunlight and liquid plant food to provide CO2 scrubbing on a small scale.

The original sample probably had a wide variety of micro-organisms, many of which are probably bubbling harmlessly away in the soup. But we're not here to create bio-soup, we're here to make algae.

It will be very nice for you if you have a microscope but you do not need one. It should be possible to obtain a single species algae culture and breed it up to production reactor populations without one. If you happen to have one, as I do not, then you can whole hog nuts and breed a pure culture from a single cell.

In any event if you want to get serious about algae you'll need to learn to culture and cultivate algae. These skills can be applied to special purpose algae species obtained from the appropriate channels. There is an appendix with more detail on obtaining single species specialized algae cultures from universities and research institutions. Expect to pay about $75 for a culture which, with sound breeding practices, is sufficient to create pure feedstock. Put some of that in a bioreactor full of pure water, nutrients and you're done.

For the rest of us we're going to isolate some algae cultures from our birdbath sample in a Petri dish (or substitute such as I use) with Agar (or a substitute).

From that we're going to identify some single culture strains (one batch of green stuff). We're going to multiply those strains in some small bottles to understand the process of scaling up a culture.

At the end we're going to create our production breeder reactor which will consist of one culture reactor which is used to maintain a constant population and two breeder reactors used to create feedstock for production reactors (in the case of CO2 scrubbers) or for feeder reactors which are moderate sized (3-5 gallon) reactors for producing feedstock for above ground pool based open pond or vertical growth closed reactor systems.

Okay with all said and done let's take a look at what we're going to need...
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SHOE00071 month ago

I doing an experimental type of agar which contains 99% dark coca for antioxidants and vitamins with yeast extract and chemicals to inhibit fungi and bacteria growth. Expect I use clover cuttings and seeds to grow. Here is the recipe.

Fungicidal yeast vitamin and mineral agar with glucose

and copper sulfate instead of sodium dichloroisocyanurate.

100 ml.

Tea tree oil=1 ml

copper sulfate = 100 mg.

dark Cocoa 99% = 5 g.

Sugarcane Molasses = 10 g.

Yeast extract = 5 g.

Grams Protien at least 3 g.

Vitamin B1 = 0.75 g +0.0041 g = 0.754 g

Vitamin B2 = 0.75 g +0.0046 g = 0.755 g.

Vitamin B3 = 1.5 g +0.016 g = 1.516 g.

Vitamin B12 = 0.5 g + 0.000021 g = 0.500021 g.

Folic acid = 1 g + 0.0004 g = 1.0004 g.

Biotin = 54 mcg. Trace.

Pantothenic acid= 12.5 mg.

Vitamin K3 = 25 mcg. Trace.

5.8 mg 1,3-diphenylurea *10 ml = 58 mg.

58 mg *20 ml/120 ml = 9.66 mg.

Requires cytokinins 1 mg per ml.

requires 20 mg.

Requires 20 ml.

Limit solubilty of 15 mg per 100 ml.

150 mg per L, divided by 10 gives 15 mg per 100 ml.

increased solubility with heat 90 to 100 degrees C.

Soak seeds (clover) 5 g per L. 10 g per 800 ml.

So soak seeds in 5 g per L of sodium dichloroisocyanurate.

soak seeds in water to reduce sodium dichloroisocyanurate

levels in seeds.




Sucrose = 16 g.

Fructose and glucose = 13 g.

Plus 5 g glucose.

Sodium salt: 160 mg + 700 mg = 860 mg or 0.860 g salt.

Calcium carbonate = 0.3 g + 4 mg = 304 mg.

Iodine (potasium iodide)= 0.015 mg.

Iron (iron fumarate) = 6 mg + 8 mg = 14 mg.

Manganese (II) sulfate = 5.5 mg.

Chronium (III) chloride = 35 mcg.

Selenium salt of sodium = 55 mcg.

Magnessium = 8 mg.

Zinc oxide = 11 mg

Potassium = 180 mg.

Malachite green = 22.5 mg

10 g *0.225/100 = 0.0225 g *1000 = 22.5 mg in 100 ml

22.5 mg/ 10 g + 1g + 5g+ 1g+ 20 g + 100 g = for 20 ml = 3.3 mg MG.

Both copper sulfate and Malachite green act as potent fungicides potentially killing the mold. The dark color agar will absorb light from the seeds but the MG will be trapped and slowly enter the seeds.

May need to adjust tree tea oil, malchite green and copper sulfate dosage.


talenco1 year ago

How can producing algae benefit from local conditions such as weather, climate, in-water application etc. so that it becomes a natural resource activity?

egbertfitzwilly (author)  talenco1 year ago

In Part One there is are two PDFs attached that speak to this. One is a summary of the NREL research and the other is actually a business model produced by the University of Alabama. The NREL concluded that algae grows everyplace naturally and the local species should be used since they will inevitably dominate any open air production methodology.

The UofA study concludes that algae can be produced sustainably and profitably in conjunction with fish farming.

Overall while clearly tank based methods provide environmental control far beyond local ambient conditions the open air methods ( raceways, ponds and son on ) might need a light break of some sort in areas which have extreme sunlight conditions such as California's Central Valley.

Does that answer your question?

Yes it does
One article mentions the requirement for two outside sources: a concentrated supply of CO2 and a saline solution to act as a medium.

Can seawater be used as a medium?

Thanks again
egbertfitzwilly (author)  talenco1 year ago

There are saltwater algae so the technology should generally transfer. A concentrated from of CO2 isn't required but the algae does need it in some form. Ambient CO2 should be sufficient. Do not forget that the algae also require other nutrients which must be supplied by some mechanism.

zwuckl1 year ago

Hey there.

I stumbled upon this instructable by recognizing your cover picture. The plant on the agar plate is clearly not an alga, but the moss Physcomitrella patens. As a matter of fact I am currently working in the lab of Ralf Reski, where this moss is our preferred organism for studies molecular biology. In addition, this is where this exact photo was made some years ago ;)

egbertfitzwilly (author)  zwuckl1 year ago

Yeah, I hijacked this photo to illustrate the instructable.

Pretty expensive
egbertfitzwilly (author)  RUSTY_duck41 year ago
I'm not sure I understand this comment. Check garage sales, you should be able to find a used aquarium for very little. Also check with your local pet supply store, they may have one ( or know of a customer ) that leaks.
try finding 1 from alibaba.com ? should have every thing u need, but will take up too a month to get to u tho....
Prodiver2552 years ago
In regards to the soil water media, would it be possible to use aquatic soil planting media in place of green house soil? If not, how would one procure green house soil? Also, does the permanent reactor vessel need to be constantly 'topped up' with freshly cultured algae or will it become mostly self sufficient? Thanks
egbertfitzwilly (author)  Prodiver2552 years ago
Any reasonablly rich soil should work, as well as a few drops of liquid plant food. A permanent reactor should be self sustaining except for the tendency of algae to spontaneously flocculate and the whole colony dies for no apparent reason. So it is prudent to maintain an algae culture for restarting. The documents I've attached to the instructable contain multiple designs for production algae ponds.
Kernel7703 years ago
Hi, really awesome instructable!
Considering the soilwater medium - I'm not sure if I understood this right; every day for three days, I add 5 tsps "cooked soil" and 5mg CaCO3 per liter - so after three days I would have 15 tsps and 15 mg per liter? (excuse me for this question)
kind regards
egbertfitzwilly (author)  Kernel7703 years ago
No, only the boiling and simmering is repeated for 3 days. Mix, boil it simmer for 15 minutes, store overnight, boil it, simmer for 15 minutes, store overnight, boil it, simmer for 15 minutes.
FuzzeeDee3 years ago
A temp controlled floating heater can be found at any pet store handling aquarium supplies.
• • • Fuzzee Dee OUT • • • }~{ <> }~{ ^~^ :-> 
blob8003 years ago
Is the baking of the greenhouse soil only required in order to sterilize it? Instead of baking in the oven, could I just sterilize it in my pressure cooker, or is the baking step required? (I would assume that baking it would get pretty smelly)
egbertfitzwilly (author)  blob8003 years ago
Absolutely, a pressure cooker would be ideal. I can't speak authoritatively to how long one might 'cook' the brew, you might check out the guidelines for 'autoclaving' which is a similar process.
AlexHRG3 years ago
Hi, first of all great Instructable! I'm more technical-minded and i have no clue what to do with biological "stuff", so this step-by-step was extremely informative!

I am wondering if you would have any source or reference to identify the cultures that have been developed? Something like a quick reference sheet for the most popular algaes found would be most helpful...
egbertfitzwilly (author)  AlexHRG3 years ago
I cannot speak authoritatively to this issue. It has several dimensions. Almost all plants are oil bearing, its a matter of how much oil one can effectively obtain. You will need an expeller press which can be purchased or fabricated depending on your skills and equipment.

Algae based biodiesel is produced with 200 proof ethanol rather than methanol, although I am not familiar with the process. To produce the ethanol you'll need to get a small fuel producers license from the ATF. It's fairly straightforward.

If you live in the southeast you might want to read the attached documents. There is a study of the folks at University of Alabama that includes a very nice algae based business model that might be exploitable.
TJBrooks3 years ago
what plants would you suggest to press oils from to produce biodiesel from methanol or ethanol that might be native to or can be grown in southeastern US?
egbertfitzwilly (author)  TJBrooks3 years ago
I cannot speak authoritatively to this issue. It has several dimensions. Almost all plants are oil bearing, its a matter of how much oil one can effectively obtain. You will need an expeller press which can be purchased or fabricated depending on your skills and equipment.

Algae based biodiesel is produced with 200 proof ethanol rather than methanol, although I am not familiar with the process. To produce the ethanol you'll need to get a small fuel producers license from the ATF. It's fairly straightforward.

If you live in the southeast you might want to read the attached documents. There is a study of the folks at University of Alabama that includes a very nice algae based business model that might be exploitable.
maliksudhir4 years ago
Hi ,
Can any one help me out in some calculation work its really very urgent , please help me out ..... i need to consume 1932.3kg/hr of CO2 with the help of Algae in a pond (water) for example Raceway pond , so i need to know the specific area to construct that pond and its sizing and dimension (length,etc) and the quantity of water needed and amount of algae used so that it easily consumes the mentioned amount of CO2 rate per hour..... please help me out soon you can also drop your suggestion and questions if any my email id is : sudhirmalik2011@gmail.com ....i will be waiting for your reply soon and i'll be highly thankful to you, if someone can help please do tell me its very urgent....

Thank you
ronmaggi5 years ago
Everyone talks about making this solar powered, but no one has talked about making it wind powered. Perhaps a small Savonius Wind Turbine belted to a small mechanical air pump inside the house?
egbertfitzwilly (author)  ronmaggi5 years ago
Actually I've got another design I've been trying to get someone to use with a Savonius or other small VAWT. In my design the wind power is used directly to provide lift in a tank. The media needs to rotate from the bottom to the top in approximately a 6 second cycle. I was thinking of a VAWT driving Archimede's screw. I'd be happy to advise if you want to take a crack at it.
I am new to this sight and very passionate about alternative energy sources. I say these things with only the deepest respect and encouragement. I love what you have posted and plan on trying to cultivate my own algae buffers. I have done a fair amount of involuntary research into wind power and felt that I could help. Wind is fairly unreliable, however when in supply there is usually alot. As a power source instead of using it to create voltage it is better stored as air pressure. A deep cycle battery (car batttery) looses power over time reducing efficiency. Either hooking the turbine up to a compressor or direct through a sterling engine pump into a reservoir would supply an extremely reliable drive source for the Archimedes screw. A HAWT would work better for drive however due to higher efficiency and torque through the length of the blades. The Savonius blades might be better suited in the tank only in a horizontal axis the bubbles would cause the Savonius blades to spin mixing the media and providing a second source of power generation.
egbertfitzwilly (author)  Lignumvital4 years ago
Tnanks for taking the time to share your comments. if I can help with your projects in any way please let me know.
aasong20015 years ago
Dear sir,Thank you very much of your thoroughly instruction. Is the purpose to "block out the light and keep it warm" by as you said to "close the jar and cover with cloth"? I intend to squeeze some "biodisel" out from Algae,how many of my "dark green bottle(1L/bottle)" needed in order to get 1 gallon of biodisel?
squeeze it

egbertfitzwilly (author)  aasong20015 years ago
Closing the jar and covering with a cloth will shut off additional light and CO2 so the algae will die and settle out. I have no information about making biodiesel from algae. There are many studies which say this is not a workable solution using native algae. If your goal is to produce biodiesel I can offer some insight into that process. Many people don't know that biodiesel can be produce with either methanol or high grade ethanol (200 proof). It is relatively easy to make 200 proof ethanol using two pass distillation in a traditional still. Oil can be crushed from many available local species using a simple oil press, often using a manual hydraulic jack for additional pressure. Sodium Hydroxide (lye) can be easily made using a microbial fuel cell (see my other instructables) to provide low voltage electricity for converting saltwater to lye. This is probably the best way to get biodiesel in any usable quantity for a stove or car.
aasong20015 years ago
Dear Sir I have many "Dark Green" bottles,but in some of them which I can see little crust, not much,I try to harvest it ,but get nothing more than my bald head,would you please instruct me to harvest it. Dark green mean good density right?mean grow success right? Thank you so much!
egbertfitzwilly (author)  aasong20015 years ago
Yes, dark green indicates successful breeding. There are several ways to harvest. Let me ask how do you want to use the algae? The absolutely simplest way to harvest is to close the jar and cover it with a cloth for a day or two. The algae will all die and settle out forming a very dark green sludge. Carefully pour off the top portion of water ( as much of the clear water as you can get out the better ). The remaining sludge can be sun dried in large, shallow trays. The resulting dried algae can be used for livestock feed, experimenting with biodiesel. The sludge can also be used directly as a fertilizer simply by spreading it around and working it into the soil. The algae can also be used in a microbial fuel cell similar to the ones in my other instructables to generate a trickle charge of electricity for recharging small batteries. The effectiveness of this is increased if one uses a 'joule thief' ( search instructables for that term).
Uncle Kudzu6 years ago
is my 4-liter algae filled aquarium a CO2 scrubber in the same way that your soda pop bottle is? i have turned off my tiny air pump so as impede the escape of CO2 at the surface, an arrangement that the other plants in the tank seem to like.
egbertfitzwilly (author)  Uncle Kudzu6 years ago
Yes, any green plant scrubs. It is my understanding that chlorella is the most efficient in terms of population density. There seems to be a strong scientific consensus that chlorella is why we have an oxygen atmosphere. Are you trying to grow algae? You might consider one of those of those overflow aerators to maximize exposure. This key issue at some point becomes light penetration which is about an inch and a half. Now the algae only require about 1-10E24 or so seconds to absorb a photon so the overflow aerators can increase population density.
no, i wasn't trying to grow algae in my aquarium, but i may have to reconsider in light of the benefits i'm reading about here. i had no idea that i had a little CO2 scrubber on the shelf beside me!

algae is the bane of the planted aquarium enthusiast; expose an aquarium to enough light to grow plants, and algae is inevitable. i have bacopa, anubias and Java moss in the tank, with recently added duckweed to actually compete with the algae for nutrients.

duckweed grows like, well, like a weed. i wonder if a dedicated container of algae with a surface of duckweed might be more efficient?

this is all very interesting; thanks for the detailed instructable!
egbertfitzwilly (author)  Uncle Kudzu6 years ago
It is my personal belief that the role of algae as part of a carbon recycling chain is being overlooked. Depending on the nature of your enthusiasm you might consider algae as planted aquarium plants.

The folks have UTEX (http://www.sbs.utexas.edu/utex/orderingAbout.aspx) have a wide variety of algae cutlures available, including some very exotic breeds.

If you flip that aquarium on its side (perhaps emptying it beforehand would be a good idea) and make it into an incubator you can culture a wide variety of carbon scrubbing and quite exotic aquatic plants.

Once you figure out how to stabilize various cultures a CO2 scrubber makes a perfect gift. I would be very pleased to assist you in working out a pilot project.
there is mt+ & mt-,how do you distinct it? I follow your instruction and I get the "green",but 2-3 days later it turn to yellow green,then pale yellow to light gray, why? are they dyeing?how to rescued them? Thank you!
egbertfitzwilly (author)  aasong20015 years ago
There are several possibilites. First algae cultures are given to spontaneously crashing but that normally happens after several weeks. Are they getting plenty of CO2? You might need to add a few drops of liquid plant periodically as well. If you have a pH test kit (say for a swimming pool) you might test the pH. If the water becomes saturated with CO2 ( too much pump, not enough water ) it can become highly acidic which will kill the algae. If you add water you need to make sure its dechlorinated.
i must say that i have never thought about algae as an ornamental aquarium plant. i'm certainly rethinking its status as a total nuisance, though. it's almost impossible not to grow the stuff, so why not put something that's so determined to thrive to good use?
neptune016 years ago
Great read! I do have a question: What is the direct benefit of growing algae beside that is a Co2 scrubber? What can dry algae be used for? If you burn this – are there some toxic gases?
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