First the reality-check:
In a sci-fi world where humans have interstellar travel but "nice" Earth-like planets are rare, what reasons might an algae farm be "better" than a plant farm, especially concerning the proletariat people living under artificial conditions (orbital ring, aerostat city, archology, subterranean, or low-gravity)? I'm trying to go for something more industrial/dystopian/repulsive to the "forest under glass" spacefarm.
- Could algae provide more oxygen or scrub more CO2 than plants?
- more Nutrition?
- a Profitable bi-product harvested from their waste or dead bodies?
- Require less skill to maintain?
- I'd assumed algae takes vast amounts of water (especially compared to aeroponics) but maybe less than conventional farming. Would algae require a large cistern or calm reservoir pools, or could it be distributed/flowing like paste or sludge through pipes?
- I couldn't find info comparing the efficiency of algae vs plants as an oxygen source.
- Algae nutrition info tends to come from people who sell algae.
- Simple organisms are more vulnerable to radiation?
Now the world-building:
Could a vascular irrigation system of algae sludge provide structural support, or be used like a hydraulic fluid to reshape the mega-structure? Could the algae cycle to the surface "skin" to get sunlight? Could the extreme poor "tap" an algae vein to get raw food?