Ornamental Sweet Potato in aquarium

I cut this branch off of a plant on a NYC street (with the owner's permission) for it's pretty color. 

October 22nd, 2016.
There are 7 burgundy leaves and 2 green leaves sprouting at the top. I wonder how well it may adapt to life in an aquarium - aquaponics!

Some plants are dangerous for fish!
 I place it in a cup of water with fish poop.

October 27th, 2016.

The roots grow visibly every day! This much grew in only 5 days! I've never seen a plant grow so fast!

October 28th, 2016.
The green leaves get visibly larger.

Hibiscus acetosella is also known as cranberry hibiscus, African rosemallow, false roselle, maroon mallow, red leaved hibiscus, and red shield hibiscus.
I am still trying to identify the plant.
UPDATE!! Thanks to your comments I was able to identify this plant as Ornamental Sweet Potato.

October 29th, 2016.
Let's test it in a small aquarium with guppy fry in it.

October 31th, 2016.
The green pair of leaves grew visibly larger, and look at those gorgeous roots!

November 1st, 2016.
The green leaf  is getting darker.

November 2nd, 2016.
A new pair of leaves sprouted 12 days from the beginning.

 November 6th, 2016.
The roots never stop growing!

November 14th, 2016.
Look at the leaves. 

What gorgeous colors!

The roots fill up the aquarium in a matter of 3 weeks. Wow!
I have to trim off roots or there will be no space for fish to swim.

I cut off a pair of the first roots at the bottom of the stem.

Then trim off the ends of all roots to an even level.
It should encourage growth of secondary"side"roots from the large roots.

November 20th, 2016.
The old leaf on the bottom of the plant has wilted during the past week.

It's time to cut it off.

November 21st, 2016.
Guppy babies are already large enough to nibble roots of the plant for occasional snacks.

November 22nd, 2016.
One month passes. The plant has 13 leaves and so many roots! I have to cut off the bottom part of the stem with some roots to make room for fish to swim.

First let's cut off the bottom 3 leaves.

Now I am going to cut off the bottom part of the stem, leaving the plant with one large root.

The plant shows incredible growth in the first month. The water stays clear and free of any odors. So far, all of this makes for a very desirable plant for aquariums.

Surprise for vegetarians!
The leaves of this plant are quite eatable. Now I can have the fanciest salad in NYC!!

The old leaves have a slightly tart taste. 

The roots have a lemon flavor.

I stay alive and in good health, even a week after eating it ;)

Have fun and happy aquaponics :)