Most of the time, what killed the cuke also killed the rest of the tank. They are, of course, sensitive inverts. ...of course, it cannot be the reefer that was at fault, so it had to be the cuke. Right?
...just like people who have issues blame hand lotion, something leeching from plastic, Windex or some other airborne spray. Well set up Calcium Reactors don't crash tanks either. Neither does somebody spraying for bugs outside and a window being cracked nearby.