I have this[1] closed ecosystem on my desk that I share with a coworker. Best decision ever.
My first EcoSphere was the little one, and the shrimp lasted a year or two.
My large sphere has been going for at least 4 years. From what I remember reading the algae will go on basically indefinitely once the shrimp died, but my little shrimp are still kicking. I've got two little shrimp in there right now, and I've seen so much.
When the shrimp die, they go away (eaten by bacteria) quite quickly. You can see the other shrimp poke at the corpses, I assume eating some of the bacteria or algae.
The shrimp also change colors. Depending on how stressed they are and a few other things they can be quite light pink (fading into white) or bright red.
My shrimp have bread at least one. I saw the little bits in the water and thought it was some sort of debris but I noticed that it was moving. They looked like little fry. I don't think any survived (I assume died or eaten), but maybe the shrimp I have are second generation or more. No real way to know.
I haven't touched it in years. It gets a dusting every few months, but there isn't much dust so it doesn't matter. I haven't done a 'cleaning' (uses a magnet sealed inside to scrap algae off the glass) in years. It sits in my apartment that I try to keep about 70 but has been as low as 60 and over 80. They seem quite resilient.
It's a very neat desk accessory. At this point there is quite a bit of algae built up in mine so it looks dirty, and a few people have asked me why I don't clean it (doesn't help since the algae is still trapped in there) or just throw it away because it looks disgusting.
But with the two shrimp living in there, I can't throw it out. They're still happy.
http://www.petshrimp.com/opaeinfo.php
Although I have to admit large-scale installation of these things in cubicles would be quite the fitting ststement for many companies...
It wouldn't surprise me much if you were right.
I don't plan to buy another though. It's been neat to watch, but after 6+ years (since I've had two spheres) I'm satisfied.
http://en.wikipedia.org/wiki/Halocaridina_rubra
If they indeed life up to 20 years the Ecosphere can hardly be very well balanced if it keeps them going for only 2-3 years.
Now we have a problem where where to put it all. I make a huge bowl of pesto every week and force feed basil to all my coworkers whenever I get a chance but I just can't get rid of all of it. I can't even make a dent in the huge bush we have.
We also grew some salad with mixed success but it's not a reliable enough source to be worth the effort.
Anyway, it's rather enjoyable. I recommend getting a small hydro garden to anyone who has any space and a little natural light in their office. Hydros need less regular maintenance (but need a bigger maintenance every now and then).
If anyone has any (preferably edible) plants that are suited for a hydroculture, please do suggest.
I'll take your excess basil if you're in the Bay Area, they're always running out at the supermarket and interrupting my pesto schedule XD
And I have some reservations about carrying green leaves in small baggies :)
Herbs are easiest I think. Mint is super low maintenance and nice for flavoring water and for cocktails. Thai basil can be tasty, and other varieties of basil are also fun. I've had no luck at all with thyme, but... eh. I'm also growing lavender just because it smells good.
Veggie-wise, you can try fast growing sprouts and microgreens, perhaps? I'm also trying my hand at some bird's eye chilies despite lack of temperature control and general warm weather in SF.
I don't know what we'll do with the starters for more plants, as I think we probably have enough basil. But, "too much basil" might be a nice problem to have.
The varieties of basil we grow start out slow but grow really fast after a few weeks. The individual plants reach a height of several feet in a month or so.
We have started out by planting a few seeds and once those plants reach some height, we take cuttings to clone them and fill the entire garden. I've had an almost 100% success rate in cloning basil, much better than any other plant I've tried.
Do not trim the growth nodes (you won't eat them anyway), just pick as much leaves as you need from the lower parts of the plants.
Basil is really easy to grow in hydrocultures, it's much more difficult to grow in soil. Rucola is the opposite, I've had zero success putting it in the hydros at the office but grows really well at home in soil.