School ecosystem experiments

[ronrca]

Your right snowplankton! If the teacher is teaching and assigning this sort of project, more information should of been provide beforehand. The teacher is responsible for the criculum(?) and should have a firm understanding of it. Otherwise, how can you really teacher something without really knowing it yourself. Its like the blind leading the blind.

"However if you put a predatory fish in a tank with a plant"
In this case, I wouldnt really classify the betta as a predator unless the tetras were fry. In the wild, bettas would be eating bugs instead of preying on other fish.

 

[snowplankton]

Initial Ecosystem:7 tetras, 3 bettas, 5 snails,10 shrimp
1 week:2 betas, 4 tetras, 5 shrimp, and 5 snails r
after 2 weeks: 2 betas, 5 shrimp, 5 snails remain
17 days: 2 betas, 5 shrimp, 5 snails remain
2 betas, 4 shrimp, 5 snails remain
46 days: 2 betas, 3 shimrp, 8 snails remain
53 days: 2 betas, 3 shrimp, 7 snails remain
2 betas, 3 shrimp, and 5 snails

LOL!!! Well at least 40% of the poor things survived the experiment. Looking at the bright side at least most of the creatures in there fared better than the Tetras...
  I don`t pretend that my aquarium is an ecosystem, but that aside I believe that I have better than a 40% sucess rate. This kid could have definately used some guidance in this experiment.

 

[FishChick]

Some of you were upset that they were not doing any water testing.  They said jar was compleatly sealed, nothing went in or out.  I have seen compleatly inclosed egosystems.  There was about a 2 and 1/2 foot clear glass ball, compleatly closed off, no way in but to break it.  It was filled about half way with water, had lots of plants and only about 10 white clouds. It was one of the coolest things I have ever seen.  As long as it got light it could be like that forever.  The one I saw was about 4 years old at the time.  I just don't think they knew much about what they were putting in to their jar.  

 

[ronrca]

Cool! I would love to see it also. But I think the main difference is like you mentioned, that students did not have enough knowledge to do the same thing. First of all the jar had more fish and less plants. Another thing is that the glass ball most likely was seeded with bacteria for the cycle. Not neccessary but likely. Another consideration is the balance between fish and plants. Im quite sure that numerous studies and hours were preformed to ensure the balance was correct. Im just curious to what happens when the plants or fish die. Another question I would have is about the nutrients that plants require like phosphates, iron, etc.