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...