Honestly, I would be far more worried about climbing the stand and tipping the tank over onto him / her. I attach all of my stands to the wall but... might be something to help reassure your wife its safe.
All of my piranhas have avoided my hand / arm when in the tank, the most likely way to be bit would be cornering them or an accidental bite when dashing around.
Any hardware store sells window locks or latches that could be used to secure the lid... just use some epoxy to attach them to the frame / glass.
All of my piranhas have avoided my hand / arm when in the tank, the most likely way to be bit would be cornering them or an accidental bite when dashing around.
Any hardware store sells window locks or latches that could be used to secure the lid... just use some epoxy to attach them to the frame / glass.