Aggressive Harlequin Rasbora

Plants are actually beneficial for your tank, I have never heard of Harlequins being that aggressive! I would add in Plants that expand, dont buy potted plants buy like Water Wisterias, Anacharis, or a Small Piece of drift wood with a plant grown on or attatched to it. Good Luck! Questions? PM me
 
Harlies are not what I'd consider good fish to cycle a tank with. They aren't as sensitive as say, Neon Tetras or anything, but I have found them to be a little on the sensitive side as fish go.

That being said, I've never had any aggression out of them. They chase each other, but I've never seen any torn fins as a result.

I think the aggression will subside as you add more of them to the tank.

Good luck with them !! I love my Harlies, and they're one of my favorite fish in the tank.
 
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