Matriarch Kiri,

Always a pleasure to hear from the Gen'an. I've recently spent some time with Canberra Star City's ecological engineering department, the team responsible for the station's closed ecological life support systems. I believe I can describe to you what their system is like, and how it can be adapted to Kinkaku-ji.

To start, the system does not require biodomes, which is both not exactly what you were asking for and something of a blessing for your station, as it means your existing food production biodomes can be repurposed for recreational purposes if you so wish. The core of the system is the algae bioreactor complex, which breeds chemical- and carbon-scrubbing algae for the air and water filtration systems. Near-perfect efficiency can be achieved with a combination of the algae filtration and standard shipborne air particle filters. Carbon removed through the air scrubbers can be used in another bioreactor to produce new activated carbon filters for the water treatment system. Between the two of these, your oxygen and water losses will be negligible.

Food is a bit trickier, but efficient hydroponics and, you guessed it, algae bioreactors are the combination of systems that resolve your problem. For the core of your foodstuffs, we have something that is effectively algae tofu; it is not particularly flavourful on its own, but it is high in protein, fibres, and incidental nutrients, and is capable of taking on and matching the flavour of whatever it is cooked with. Some of our culinary team believes that what we have come up with is more or less Synth Paste, just more rigid and capable of being used to relatively faithfully emulate solid foods.

Bootleg Not-Synth Tofu is of course rather boring, and not suitable for long-term use on its own, so we use a few dozen hydroponics centres with thorough use of vertical stacking to ensure maximum space utilization and automatic climate control in tuned to the specific crop being grown in each hydroponics centre. A series of calcium nitrate rich liquid fertilizers are dispensed at different levels for different crops automatically depending on what stage of growth they're in, maximizing crop output and decreasing the length of growth cycles versus manual hydroponics work. It's an effective way to grow all sorts of fruits, vegetables, and lighter grains to improve your dishes.

Traditional biodomes are only effective for growth in two dimensions, but we are in space. We can put crops, filtration systems, and water reclamation in all three. I'm sending over some examples of fresh foodstuffs from Canberra's ecological systems for you to sample and have your cooks experiment with. If the produce is sufficient for your needs, we can get some folks from the ecological engineering team over to survey possible locations in the station to install bioreactor complexes and hydroponics centres.

And if for some reason you miss the texture of Synth Paste, I'm pretty sure that a blended mix of three parts of our algae tofu to one part water is damn near the exact same thing.

Warmest regards,
Taskmaster-Adjutant Harold Kane
Natio Octavarium

Matriarch Kiri,

Our bioengineering teams use a few different species of algae to accomplish the goals of the CELSS. They will be able to seed the system appropriately in conjunction with your engineers while the system is being built. The complete bioreactor complex shouldn't be terribly expensive to build, but we estimate that a full food, oxygen, and water support system for one person averages out to about four cubic metres of space. The hydroponics system takes some time to start from scratch but we can produce some clones of our existing fruits and vegetables and you'll have your own year-round continuous harvests of fresh produce within a month.

Most hydroponic plants take up a similar amount of space as they would in the ground, but with slightly denser horizontal packing and the advantage of being able to be vertically stacked. Once the system is live and producing food, you can easily expand it by cloning off your existing plants. If you can grow it in the ground, you can likely grow it just as well if not better in water, as you can tailor the nutrient formula to the exact plant. The tomatoes we've been growing are a good bit larger and juicier than imported ones, and they seem to grow faster as well.

The algae tofu tastes similar to soy tofu, but slightly more kelp-y. If you wanted really cheap staple food, well... there's always yeast. I would highly recommend that if you plan on building a yeast farm, you keep it somewhere isolated and far away from everything else. It's effective, extremely inexpensive protein, but gods and monsters does it ever make for a section of a station that smells like a brewery. As for the health effects, our staple foods are all grown on Canberra and have been since not long after its founding. We all seem to be in pretty good shape. Most of our imported foods are, erm, "liberated" from the cargo holds of Samura transports passing through the Barrier, so I suspect that you and your people will get on just fine with such a similar complete diet.

Warmest regards,
Taskmaster-Adjutant Harold Kane
Natio Octavarium