<p>Here's what I think.</p>
<p>It's really "flowery"... you're trying to say too much. It doesn't flow very well, and it's not that easy to read. I very much agree with WindCloudUltra: more active sentences. </p>
<p>Harvard needs to know who you are. From your essay, I know that you like aquariums and you've learned a lot from fish. But why would you be a good addition to the Harvard student body? What can you contribute to Harvard? The essay is a chance for Harvard to learn more about you as a person- you've (presumably) got great stats and a great resume. Harvard will be interested in the fact that you are an aquarist, but to stand out in the applicant pool, you must intrigue them. Why should they admit you? Why are you special?</p>