When I just got interested in Aquatic Ecology I wanted a testing setup to experiment and to test hypothesis. I was interested in water chemistry and aquatic life and as a hobby I kept fish and reptiles. So I was known with animal habitats but I was educated as an ICT professional. When I told family and friends about my idea I got the question "Have you ever heard of systems for space research? I think there was a small aquarium with fish they launched in to space for research. The Sebas or something like that, you should take a look at that some time". The C.E.B.A.S. or Closed Equilibrated Biological Aquatic System what it's called is a closed aquatic ecosystem with plants, aquatic snails and fish that was used for research in space. Unfortunately it is to advanced and to expensive for a home setup. And I didn't want one I wanted 2 groups a study group and a controle group. After reading numerous scientific papers on space habitation, space research and ecology the ABS or Autonomous Biological System seemed to be the most logical and reliable tool.
The Autonomous Biological System was used for experiments in space and circled the Earth onboard the MIR and the Space Shuttle. The original version on the right was a simple 900 ml system with a simple lid on top. But for me at home it had some big advantages. I could construct them from easy obtainable materials and a plastic lid made it easy to drill holes to add a pH sensor. Besides the pH sensor for monitoring the overall water quality improving the lid looked a good idea. I intended to use my systems for a long time without worrying about a lid that got looser and looser while opening and closing it time after time.
My first generation Autonomous Biological Systems were made from 1.5 liter glass vases with a PVC plumbing cap as lid. Such plumbing caps are normally used in sewerage systems and are known for their air tightness. The rubber ring that is in the lid creates an air tight seal preventing air leakage and gasses escaping the system.
I used these first generation systems for two study sessions of 3 months before I added some new parts and started working on the Bioregerative Life Support Systems itself. The system displayed on the left had three basic functions to support the gastropod population; food and Oxygen production and the reduction of CO2. Eventually the systems collapsed after 3 months and I realized there was still a long road to go before a system like this can support larger organisms than water fleas and ostracods. In 2025 I've tested the third generation resulting in the development of the fourth generation with improved Life Support System.
Ijiri, K., Mizuno, R., Narita, T., Ohmura, T., Ishikawa, Y., Yamashita, M., ... & MacCallum, T. (1998). Behavior and reproduction of invertebrate animals during and after a long-term microgravity: space experiments using an autonomous biological system (ABS). Biological Sciences in Space, 12(4), 377-388.