I ignorantly bought a "self-sustaining" shrimp eco-sphere.. Help me save them!

Hi all,

I was in Orchard Central today when I saw a booth opened by CRS Haven. They were selling little containers/tiny "tanks" containing a few shrimp, some coral, algae and gravel.

The storekeeper boasted that the self-sustaining containers were extremely low-maintenance. There's no need to feed, clean or even change the water in the container- all it needs is indirect sunlight, which will grow the algae, which is in turn eaten by the shrimp. They would also live several months, even a few YEARS in that little container!

Me, being the easily-excited and impulsive girl that I am, jumped at the opportunity to buy one. No need to feed, clean or maintain?! Sounded too good to be true! I'd also seen some really expensive sealed spheres that worked the same way, and had always wanted to get one but was deterred by the price. I'd also seen a huge one in the Singapore Science Centre that had been there for almost 20 years, so I figured it must be safe!

I paid a hefty $120 for a container containing 6 shrimp, and also got a small packet of food. He directed me to put in one of the tiny pellets once every 2 weeks to give extra nutrients to the shrimp. He did indirectly state that it was unnecessary, and the pellets were like "vitamins" to keep the shrimp healthy and happy. I also bought a bottle of "nutrient water", which he said to use in topping up the water when the water level dropped.

I happily (and carefully) transported my little world home, and admired them swimming around energetically before googling "ecospheres". Oh god! I found out that it's torturous and cruel for the shrimp, and that they are very hardy, which is why they can live up to a few years in the container by STARVING themselves to death.. But they are actually are capable of living over TEN years in a good habitat

They container has a lid which can be opened, and I'm hoping to be able to save the poor shrimp and give them long, happy lives!

I used to keep 1 or 2 crayfish, but I'm absolutely clueless about shrimp, some kind souls please help me out!

I found out they're Volcanic Shrimp, also knows as Hawaii Red Shrimps. Is there any set up I can get on a relatively low-budget, and relatively low-maintenance?

Is it possible to keep them without a filter? What type of food, what's the smallest-sized tank I can get for them (not much room for like a footlong tank as I've moved to a smaller house..), what water conditions? Argh, so stressful.. I regret having made such an expensive AND cruel purchase!

Please help, bros!