I Was Given Alot Of This Plant

[ICEEGRL]

I took several pics of the plant so you can hopefully tell me what it is.
I rehomed my mollies and pleco with my neice in law's boyfriend. He has some large tanks and a pond. While there we were talking, and he said he had lots of extra plants in the pond. He gave me a bunch of this. He just doesn't remember what the name of it is. He got it at a pet shop. It is supposed to be an aquarium plant.
Please take a look and tell me what I have.

This last pic has some ghost looking things in it that I couldn't see with my eyes, but it was there when I blew up the pic. What are they? Is that really small critters?
Thanks for all the help!

 

[Miss Wiggle]

elodea densa i think

 

[ICEEGRL]

Cool. Thanks.
One more question... It was floating in his pond. It is really nasty and sort of slimy. How do I clean it? I have most of it in a big bowl infront of my window for now. I have to clean it before I can plant it in my tank. I have rinsed it, but that didn't do alot. What is the process?
Thanks again!

 

[Sibelius]

It is elodea. I'm not sure I'd risk putting that particular plant in my tank, with those things on it, they could be a form of pond insect that don't do the tank any good. I'd probably get some from another source, that's clean. Elodea isn't expensive.

 

[ICEEGRL]

Ok. You scared me. What was in the pics was in the tank, and the rest was in a bowl. It is out of that tank now. All of it got the cleaning of a lifetime. It is mostly all stems now. If it lives great, and if it dies I will buy new plants. I put it in a tank with pest killer. In a week or so I will replant it if it looks ok.
The tank it was in got cleaned too. It had small fish. I hope they will be ok. I transplanted some watersprite in to replace it so the fry would have places to hide. Should I put something in that tank for pests too or will it be ok with just the 50% water change and bottom cleaning? I also added a polishing pad to the filter to catch the very small stuff, but the filter isn't very strong due to it being a fry tank.
I washed it in old tank water and added it because I read that the micro organisms in the plants would serve as a type of food for the fry. Yet again I have learned to ask here first before doing anything new in a tank.

This is what the tank looks like now

Thanks