Culturing Algae

[lukem321]

If you want to culture algae, the first thing you should consider is what kind of algae you want, and how much you want to produce. If you want high yields in the shortest amount of time, it is best to buy pure algae cultures online. I used Florida aqua farms (http://florida-aqua-farms.com) to start a pure chlorella culture and am very happy with the results. Otherwise, and in the case of my pediastrum culture, you can just fill a bottle with pond water and let the algae accumulate. For either method, I use 2 liter soda bottles as my culture vessels, and have one air pump that aerates my 4 culture bottles (with my current air pump, I'd say I could aerate up to 6 bottles at a time). Also, I keep the bottles next to a window facing northeast, and I have lamp on them until midnight when I go to sleep (it is best not to keep them in direct sunlight, but you also want 18+ hours of light exposure per day). If you start a culture with pond water, try to get as much algae as you can, but try to limit other things such as sediment and detritus from getting in. The culture will start very slowly, I think it took about three weeks for my starting culture to become dark green. Once your culture is sufficiently dense (dark green), you can split the culture into 2 bottles and fill them with water. From then on, the cultures should be dense and ready for splitting (or harvesting) every 8 days or so. The water you use should not contain chlorine, so treated tap water should be boiled or left out to sit for a day before use. Lastly, and I think this is important for optimizing growth, I add algae grow (http://florida-aqua-farms.com/shop/micro-algae-grow) to the water to provide nutrients and vitamins. The problem with pond water as opposed to buying algae is that the algae is limited by predators such as rotifer and amoebas (but I like them so it doesn't bother me), making it less practical for mass production of algae. On that note, my pediastrum culture contains a lot of cool amoebas in very high concentration that I rarely get to see in samples, even from the pond they came from . If you have any questions, feel free to ask

My current setup of 4 chlorella culture bottles

A view of the old pediastrum culture, notice the chunks of detritus present because I used pond water.

[75RR]

Amazing setup. I was expecting a petri dish!

For now just a couple of questions.

How many pediastrum do you need in a sample to start a culture from pond water?
Are you careful to remove other algae from the sample before you start?

Lastly, you seem to have more pediastrum than one would need to obtain good samples to photograph.
What do you do with them? You mention harvesting?

[Crater Eddie]

Very cool! I have made many random culture jars, but never anything like this.

[lukem321]

Thank you both for commenting.

If you use this method you're going to want as much algae as you can get to start a culture. It is possible to isolate cells of a specific species of algae, but it would require months for the few isolated cells to form a dense culture. What I recommend is to just fill a bottle with the greenest water you can find and give it time. One type of algae will grow the fastest and dominate the culture. Each time you split and dilute your water the dominant algae will outgrow it's competition so you will get a purer and purer sample. The downside with this is that you cannot really choose which algae you are culturing, and that's one of the benefits of the pure cultures for sale online.
To answer your last question, this was all just a fun experiment for me . I may feed the algae to baby fish I am raising, or feed it to future rotifer and/or daphnia cultures used to feed the fish fry. Who knows, I've got a lot of time on my hands

[Crater Eddie]

I think I just found a use for a few empty wine bottles.
Do you use an air stone, or just open ended tubes for aeration? Do you let it bubble vigorously, or turn it down to a slow dribble of bubbles?
CE

[lukem321]

I commented on your post, before I saw this, saying that I do not use an airstone because I read that small bubbles can be bad for microorganisms. Also, I don't think the amount of air matters very much. With the way my current system works, I have 1 valve that splits an output into three cultures, and the second output goes entirely to the fourth culture. This means that one culture gets three times as many bubbles as the other three, but they all seem to be doing the same thing. From my experience, the main purpose of the bubbles is not to provide co2, but to keep the cells suspended in the water. Knowing this, some algae cultures will need more air than others. I noticed that my Pediastrum were much heavier than my chlorella because every night when the pump would be off the pediastrum would settle to the bottom, while the chlorella would stay suspended in the water.
Luke