as we all know that tanks need regular water changes even if it is just to replenish the depleted micronutrients and minerals that all life requires. This is especially true for complex plants, even algae which they claim the shrimp live on will require micro nutrients and trace elements.
Actually the biggest reason we do water changes is the remove the excess minerals that are in tap water, in the food we feed the fish, and minerals from any treatments we apply to the tap water before putting it in. If you don't let the water evaporate or add food the water chemistry will stay nearly constant.
I believe that theses units are a closed system which does not allow for oxygen exchange with the outside environment another important function of a working ecosystem.
Actually air trapped at the top of the ecosphere will slowly defuse throughout all the water. Air diffusion through the water is not fast enough for fish but is fast enough for shrimp. Additionally the alqae inside will produce oxygen and food the shrimp need.
The shrimp generally used in these slow death traps
If you look on the web you will find comment people that own Ecosheres. Many state that they have shrimp that have stayed alive in excess of 10 years. Some as long as 15. If you don't do water changes or feed fish in an aquarium, all the fish will die in less than a month. Obviously something must be working right for a shrimp to live that long.
If you don't supply the exact amount of heat/light as an energy input (and I'm sure all of you who've unintentionally grown algae in your tanks are all certain that you can get this balance perfect in future, aren't you), then the algae with either overgrow, or undergrow, throwing the balance and wiping out the whole thing. After that you have a fairly expensive and somewhat cloudy crystal ball.
People that own them have commented that after the last shrimp dies you are left with a cloudy crystal ball. they also frequently state they are only left with one shrimp after 5 or fewer years. in my opinion the biggest problems with the Ecosphere is that it is too small and they don't specify the amount of light they should get per day (Lumen hours or PAR hours).
Most people probably over estimate how much light they are giving it. Most are probably giving it insufficient light. In sufficient light mean insufficient algae growth,O2 production, and less food for the shrimp. Also the small size will make it susceptible to larger temperature changes. Also the smaller size means means a sudden change in light levels food will levels and oxygen levels to swing wildly.
Honestly, get her a cherry shrimp tank, far more fun.
I would second that. However I would suggest using a sealable glass container rather than a regular aquarium. Such as the 2 gallon version of this (
http
/www.diy-ecosphere.com/thread.php?lng=fr&cat=1&pg=319&id=2 ). That way if she wants she can try and creat here own ecoshere. On that she can open periodically if needed.
"These ecospeheres basically remind me of those plant terrariums that where all the rage years ago, but even these fail without up keep. The soil goes sour and the plants deplete all the available nutrients."
The link below goes to a story about a guys plant that has been growing in a sealed glass bottle. The last time he watered it was 40 years ago, 12 years after he first sealed it. A self sustaining environment in a sealed container is possible if you spend the time to set it up carefully and if necessary open it maybe once to correct an imbalance. The Ecoshere product is assembled and shipped with very little time to allow it to stabilize. A lot of people have set these up. How many that go past 5 years? I don't know but some probably do.
http/www.dailymail.co.uk/sciencetech/article-2267504/The-sealed-bottle-garden-thriving-40-years-fresh-air-water.html
https/www.google.com/search?q=diy+ecosphere&espv=2&biw=951&bih=604&tbm=isch&tbo=u&source=univ&sa=X&ved=0CCQQsARqFQoTCJm0q7KTgMkCFRfsYwodTkYO8g&dpr=1#imgrc=xJI3OS7QY6-_1M%3A
