I accidentally posted this in Saltwater forums a little while ago, so I'm going to repost here:
"I have one of the plants that is in the center of the picture on this website: PETCO Fluorescent Aquarium Plants at PETCO
Occasionally, I would find dead fish in there and it was a real nuisance to clean out, but I assumed it was a comforting place for them to go hide or whatever when they were near death. However, today I was cleaning the tank and noticed yet another dead one. I pulled the plant out and left the room to pour some fresh water to refill the tank with. When I came back, the plant was wriggling! I quickly dumped the neon tetra back into the tank and he has been swimming around fine.
So now I know that for some reason, this plant is luring fish to their deaths. Obviously I've removed the offender, but I wanted to know if anyone had some insight. What do you think could cause this? Does the fluorescence attract them when it becomes dark outside? Or is it possible that they don't have enough room to swim freely and become entangled? Or is it simply the wrong shaped plant for the wrong fish? No matter the cause, I won't be putting it back into this aquarium setup. But it would be nice to get some opinions on the root problem so that I could avoid it with similar plants in future setups.
Thanks in advance!"
I was then asked for some clarification, so I'll address those concerns below. willow posted that it is not likely my plant that is the problem.
My tank is only 2 gallons (can't keep anything bigger in my apartment).
It has been set up for a little over a month now, with Glow Light and Neon Tetras (the Glow Lights were the first fish I bought and then replaced by Neons as they died during the cycling).
As of yesterday, all my chemical balances were good. Ammonia was a little high (.5 whatever the units are), but I've come to expect that whenever I get my water tested (because I get it tested before I do a water change) and I put in ammonia neutralizers and perform water changes to keep it down.