Howdy, while watching an episode of Ancient Aliens, the topic of the Manna machine was discussed, which is a machine supplied by the aliens to grow algae (chlorella) for the Israelites for food during the 40 year trip across the Sinai desert. Anyway I was struck by the the detail that it needed to be cleaned every 7 days in order for it to work, which seems to be one principle that everyone agrees on for an algae scrubber. The Manna Machine - Wikipedia
That's pretty funny. However we have advanced since then and can now go 10-14 days or more. They didn't have LEDs back then
But they did have these... maybe used ?...nobody knows.... apart from that funny guy on AA who desperately needs a haircut.