I'm a big fan of iterating on designs so I made version zero to just place in our south-facing living room for now. It's just a USB/battery/solar powered air bubbler connected to a 5L water bottle - as basic as possible to get something going while I figure out other components. I bubbled the water for a few days before adding half of the algae as I wasn't sure how high the chloramine content was. For an algae species I chose Nannochloropsis as they're often used in research due to their efficiency, and they're easily available too. I added a bit of algae nutrient too, both from UK aquatics supplier Reefphyto.

The algae look like they're doing great after about a week. I want to get them outside where it's sunnier but the ideal location is about 50M from the house - I'm working on a solar powered controller for the pump that will also let me record some environmental stats via radio/WiFi.

So far the biggest unknown is how to measure algae growth, which will be essential for gathering good data and making decisions like when and how much to harvest. One for a future post.