Opinions wanted:

I'm thinking about getting a Snowflake Eel. I have a 75 Gallon reef. (fish,
rock, sand, coral, hermits, snails etc)
I've read that they are really only a threat to crustations and escaping out
the top of the tank.
What else do you think I may need to know ?
How fast do they grow ? If I were to purchase a 10" specimen it would be
nice to know
how long before it becomes "GINORMOUS" About 20"

Thanks,
Chris