Self-Sustaining Aquarium Pond Snails and Elodea Testing

Hello everybody.
I have been doing different experiments to find out what it takes to build small size self-sustaining aquariums with guppies.

 I need to find plants and critters that can be used in aquariums to maintain sustainability.
Fast growing Elodea plant and often reproducing pond snails that I have in all my aquariums, seem to be good candidates for this purpose.
 Though, pond snails need access to atmospheric air for oxygen to breath.
Well, let's check how Elodea plant and pond snails perform in an enclosed tank.

I use a 2 liter glass jar with lid.

Add dechlorinated water.

Add 2 cuttings of Elodea.

Add 4 about 0.5 cm large pond snails.

Also, I added a seashell.

And seed shrimp.

 Give snails a pinch of homemade fish food flakes.
It should boost algae growth.

Close the jar with a lid.

I flip the jar to seal the lid with water.
Yep, some water leaks out.

The leak should stop once the pressure inside of the jar gets to the same level as it is outside.

December 21st, 2018
All set.
I put the jar on a windowsill for direct sunlight to boost algae growth.

December 25th, 2018
 Snails crawl around.
I don't see them laying eggs at all.

Many Elodea leaves wilted.
 I forgot to mention duckweed that gets in along with Elodea.

January 2nd, 2019

Snails and seed shrimp feed on the wilting Elodea.

January 19th, 2019
Elodea lost many leaves in the first couple weeks.

Now it looks stabilized.

February 5th, 2019
I see 2 active snails and seed shrimp.

This snail is dead.

It did not move in a couple days.

February 8th, 2019

This snail is alive.

I see 3 young snails.
All 3 are dead.

Here is one.

And here are two others.

February 17th, 2019
Only one alive baby snail remains in the tank.

And there are seed shrimp dancing around everywhere.

2 months long experiment is over.
Have fun and happy aquariums :)